Showing papers in "Journal of Experimental Psychology: General in 1981"

On the relationship between autobiographical memory and perceptual learning.

Abstract: Although the majority of research on human memory has concentrated on a person's ability to recall or recognize items as having been presented in a particular situation, the effects of memory are also revealed in a person's performance of a perceptual task. Prior experience with material can make that material more easily identified or comprehended in perceptually difficult situations. Unlike with standard retention tests, effects of prior experience on a perceptual task do not logically require that a person be aware that he or she is remembering. Indeed, amnesic patients purportedly show effects of practice in their subsequent performance of a perceptual or motor task even though they profess that they do not remember having engaged in that prior experience. The experiments that are reported were designed to explore the relationship between the more aware autobiographical form of memory that is measured by a recognition memory test and the less aware form of memory that is expressed in perceptual learning. Comparisons of effects on perceptual learning and recognition memory reveal two classes of variables. Variables such as the level of processing of words during study influenced recognition memory, although they had no effect on subsequent perceptual recognition. A study presentation of a word had as large an effect on its later perceptual recognition when recognition memory performance was very poor as it did when recognition memory performance was near perfect. In contrast, variables such as the number and the spacing of repetitions produced parallel effects on perceptual recognition and recognition memory. Following Mandler and others, it is suggested that there are two bases for recognition memory. If an item is readily perceived so that it seems to "jump out" from the page, a person is likely to judge that he or she has previously seen the item in the experimental situation. Variables that influence ease of perceptual recognition, then, can also have an effect on recognition memory, so parallel effects are found. The second basis for recognition memory involves elaboration of a word's study context and depends on such factors as level of processing during study--factors that are not important for perceptual recognition of isolated words. Comparisons of perceptual recognition and recognition memory are shown to be useful for determining how a variable has its effect. Effects of study on perceptual recognition appear to be totally due to memory for physical or graphemic information. Results reported are also relevant to theories of perceptual learning. A single presentation of an item is shown to have large and long-lasting effects on its later perceptual recognition. At least partially, effects of study on perceptual recognition depend on the same variables as do effects on more standard memory tests.

Selectivity of learning caused by affective states.

Abstract: SUMMARY We investigated how emotional states influence learning and memory. Specifically, we asked whether people's remembering of a text varies with their emotional mood at the time they read or recall a text, A theoretical framework is proposed that represents an emotion as a unit within a semantic network that encodes memories. It also assumes that by spreading activation, a dominant emotion will enhance the availability of emotion-congruent interpretation s and the salience of congruent stimulus materials for learning. To collect relevant observations, powerful moods were induced by posthypnotic suggestions. Experiment 1 found that happy or sad readers identified with, and recalled more facts about, a character who is in the same mood as they are. In Experiment 2, this selective recall by character could not be produced by inducing the mood at recall after subjects had read the story in a neutral mood. In Experiment 3, subjects read a text wherein one character described many unrelated happy and sad incidents from his life. Readers were made to feel happy or sad while reading and, independently, while recalling this text. Mood during reading caused selective learning of mood-congruen t incidents, but mood during recall had little effect. Experiment 4 replicated with this one-character narrative the finding that inducing the mood during recall only produced no selective recall of its happy versus sad incidents. Experiment 5 pitted the happy-sad nature of the incidents against the mood of the character narrating them. Readers learned more mood-congruent than mood-incongruent incidents, but did not learn more about the mood-congruent character. Thus, rather than identifying exclusively with the same-mood character, subjects selectively learned whatever affective material was congruent with their emotional state. The mood-congruity effect is consistent with the network theory of emotion and memory. Several more specific hypotheses were proposed. One is that mood-congruent material is more memorable because it elevates the intensity of the subject's feelings, whereas mood-incongruent material diminishes mood intensity. A second is that subjects focus on moodcongruent material in order to explain and justify their hypnotically instructed emotion. But further results did not support this attribution hypothesis. A third hypothesis is that mood-congruent material may be more likely to remind the reader of a similar experience, and this promotes learning.

Phonemic Restoration: Insights From a New Methodology

Abstract: Phonemic restoration is a powerful auditory illusion in which listeners "hear" parts of words that are not really there. In earlier studies of the illusion, segments of words (phonemes) were replaced by an extraneous sound; listeners were asked whether anything was missing and where the extraneous noise had occurred. Most listeners reported that the utterance was intact and mislocalized the noise, suggesting that they had restored the missing phoneme. In the present study, a second type of stimulus was also presented: items in which the extraneous sound was merely superimposed on the critical phoneme. On each trial, listeners were asked to report whether they thought a stimulus utterance was intact (noise superimposed) or not (noise replacing). Since this procedure yields both a miss rate P(intact/replaced), and a false alarm rate P(replaced/intact), signal detection parameters of discriminability and bias can be calculated. The discriminability parameter reflects how similar the two types of stimuli sound; perceptual restoration of replaced items should make them sound intact, producing low discriminability scores. The bias parameter measures the tendency of listeners to report utterances as intact; it reflects postperceptual decision processes. This improved methodology was used to test the hypothesis that restoration (and more generally, speech perception) depends upon the bottom-up confirmation of expectations generated at higher levels. Perceptual restoration varied greatly wih the phone class of the replaced segment and its acoustic similarity to the replacement sound, supporting a bottom-up component to the illusion. Increasing listeners' expectations of a phoneme increased perceptual restoration: missing segments in words were better restored than corresponding pieces in phonologically legal pseudowords; priming the words produced even more restoration. In contrast, sentential context affected the postperceptual decision stage, biasing listeners to report utterances as intact. A limited interactive model of speech perception, with both bottom-up and top-down components, is used to explain the results.

Evaluation of evidence in causal inference.

Abstract: : In three experiments, we investigated what evidence people use in making inferences about causality in complex and uncertain situations. Given evidence consisting of multiple observations of some outcome, with each observation including information about the presence or absence of that outcome and of some of its possible causes, subjects estimated the strength of the causal relationship between the outcome and a predetermined possibly-causal event. Over problems and over experiments, the nature and strength of evidence supporting the causal role of the hypothesized cause varied along many dimensions. Using regression-modeling, we found a set of five evidence types that together gave a good account of subjects' judgments. Four of the independent variables in this model directly concern the relation between the hypothesized cause and the outcome (confirmation by Joint Presence and by Joint Absence of target and outcome, and disconfirmation by violation of sufficiency and of necessity of the target for the outcome), and the fifth represents the goodness of alternative causes as explanations for the outcome. Over the experiments, involving four groups of subjects and five sets of problems, this single linear model accounted for 84 to 90% of the variance in each problem-set. (Author)

An examination of the alleged role of "fixation" in the solution of several "insight" problems.

Abstract: SUMMARY A series of experiments were conducted to examine the purported role of fixation in the solution of several insight problems, such as the nine-dot and triangle problems. It has been commonly accepted in psychology that such problems are difficult because subjects are fixated on unwarranted assumptions concerning how the problems are to be solved. In the present studies, subjects were disabused of these allegedly fixating assumptions in order to see whether quick and direct solution of the problem would then follow. For example, subjects working on the nine-dot problem were told that the problem could be solved only by extending their solution lines outside the boundaries of the square formed by the dots, and subjects working on the triangle problem were told to work in three dimensions. The basic finding was that removing the alleged fixation did not result in sudden and direct solution of the problems, indicating that fixation was not a very important factor in making these problems difficult. It was also found that significant facilitation of solution in these problems could be brought about only by giving subjects relatively detailed information about the solution. It was concluded that the terms fixation and insight are not useful in describing the processes involved in the solution of these problems, and the role of problem-specific knowledge in the solution of insight problems was emphasized. The relationship between the present findings and other recent work on problem solving is also discussed.

Practicing the two disciplines for relaxation and enlightenment: Comment on "Role of the feedback signal in electromyograph biofeedback: The relevance of attention" by Qualls and Sheehan.

Abstract: Qualls and Sheehan's finding of a disordinal Personality Trait X Treatment interaction underscores the indispensability of both disciplines of scientific psychology for the study of some important phenomena. It is noteworthy that such interactions are entirely congruent with a reasonable conception of personality traits as dispositions, that is, as inherently interactive functional units. Using absorption, the trait studied by Qualls and Sheehan, as an example, it is shown how an empirically corroborated interactive trait concept can be used as a source of ideas for further Trait X Treatment studies and even for pure experimentation. Specifically, a distinction is proposed between two hypothetical mental sets: an experiential (or respondent) set and an instrumental (or operant) set. High-absorption subjects differ from low-absorption subjects in that the former appear more experientially and less instrumentally disposed than the latter. This hypothetical difference, in conjunction with the assumption that relaxation can function respondently as well as operantly, can be used to account for Qualls and Sheehan's findings and suggests additional investigations as well.

Aging and skilled problem solving.

Abstract: Information-processing models of problem solving too often are based on restrictive age ranges. On the other hand, gerontologists have investigated few problem-solving tasks and have rarely generated explicit models. As this article demonstrates, both fields can benefit by closer collaboration. One major issue in gerontology is whether aging is associated with irreversible decrement or developmental plasticity. If both processes occur, then an appropriate strategy for investigating aging is to equate age groups for molar problem-solving performance and search for differences in the underlying components. This strategy was adopted to examine the relation of age and skill to problem solving in chess. Chess players were selected to vary widely in age and skill such that these variables were uncorrelated. Problem-solving and memory tasks were administered. Skill level was the only significant predictor for accuracy in both a choose-a-move task and a speeded end-game evaluation task. Age (negatively) and skill (positively) jointly determined performance in an unexpected recall task. Efficient chunking in recall was positively related to skill, though negatively related to age. Recognition confidence, though not accuracy, was negatively related to age. Thus despite age-related declines in encoding and retrieval of information, older players match the problem-solving performance of equivalently skilled younger players. Apparently, they can search the problem space more efficiently, as evidenced by taking less time to select an equally good move. Models of chess skill that stress that role of encoding efficiency, as indexed by chunking in recall, need to be modified to account for performance over the life span.

Depression, nondepression, and cognitive illusions: reply to Schwartz.

Abstract: In his comment, Schwartz argued that the Alloy and Abramson findings call into question the hypothesized causal link between learned helplessness and depression. Schwartz's contention is based on his interpretation of the Alloy and Abramson findings as showing that nondepressives cannot detect noncontingency. Although we argue that Schwartz has misinterpreted our data, we agree with his general contention that nondepressives may be relatively invulnerable to depression. We discuss the implications of our data for the learned helplessness theory as well as for other cognitive theories of depression. In addition, we evaluate Schwartz's intriguing motivational account of depressive accuracy in judging response-outcome contingencies. Finally, in response to Schwartz's question of whether nondepressives' errors in judging contingency are really errors at all, we suggest it is important to distinguish among error, irrationality, and maladaptiveness when discussing cognitive bias.

Role of the feedback signal in electromyograph biofeedback: The relevance of attention.

Abstract: This article describes two experiments designed to examine the hypothesis that the critical role of the feedback signal in frontalis electromyograph (EMG) biofeedback is an attentional one. In both experiments, high- and low-absorption subjects were assigned to either a biofeedback condition, a no-feedback condition, or an attentional demand condition in which external stimuli, related to relaxation, were presented as an attentional focus. The two experiments differed essentially in the type of attentional demand condition that was employed and varied the compelling nature of the demand on subjects for an external attentional focus. The pattern of results was consistent with the attentional hypothesis. For low-absorption subjects, performance in the biofeedback and attentional demand conditions was equivalent and appreciably greater than in the no-feedback condition. For high-absorption subjects, an interference effect of biofeedback was observed, but data indicated a similar interference effect on the performance of subjects when the attentional demand condition was most compelling. The pattern of results obtained point to the special relevance of attentional processes and highlight their lack of emphasis in contemporary theoretical models of EMG biofeedback.

Strategies of arousal control: Biofeedback, meditation, and motivation.

Abstract: A series of four experiments assessed the effects of instructions to lower heart rate on heart rate change and general arousal reduction. Various conditions of biofeedback, cognitive load, incentive, knowledge of results, and the experimenter-subject relationship were tested. Experiment 1 compared physiological responses to the delivery of direct organ feedback (i.e., heart rate) with responses to electromyographic biofeedback from the frontalis muscle area and with responses to a nonfeedback tracking task. The results suggest that neither heart rate nor muscle tension feedback is an especially powerful method for achieving sustained reductions in heart rate. Furthermore, although some specificity of physiologic pattern is apparent, biofeedback is no more effective in lowering general activation level than simple instructions to relax accompanied by a general knowledge of results. The second experiment was designed to assess the role of cognitive load in arousal reduction. Heart rate biofeedback was compared with a procedure involving minimal external information processing--the secular meditation exercise of Wallace and Benson. The results indicated a clear superiority for the meditation strategy in effecting reductions in cardiac rate and lowering activation. However, in a third experiment, meditation subjects lowered heart rate much less than observed in the previous study, and this time the reduction did not exceed that achieved by feedback subjects. Subsequent analysis suggested that the quality of the subject-experimenter relationship (active-supportive vs. formal-distant) was a significant variable in accounting for outcome differences. The above hypothesis was supported by a fourth experiment. Under conditions of high subject-experimenter involvement, the superior meditation performance of Experiment 2 was reproduced; under low-involvement conditions the Experiment 3 result of no difference between training groups was obtained. The findings suggest that the effectiveness of any method for achieving relaxation (or physiological control) rests on a complex interaction between informational and motivational imperatives of the stimulus context and definable aspects of the interpersonal exchange between subject and experimenter. This research raises serious questions about the effectiveness of the usual biofeedback paradigm as an aid to arousal reduction and the cost efficiency of its applications in the clinical situation. Furthermore, these results demonstrate the great power in relaxation experiments of psychosocial and other moderator variables, and signal the practical difficulty of their control when these variables appear to be as potent in changing physiology as the primary training methods.

The acoustic correlates of "speechlike": a use of the suffix effect.

Abstract: SUMMARY The stimulus suffix paradigm has been used to establish the importance of precategorical acoustic storage (PAS) as a theoretical construct in the investigation of attention and speech perception. Morton and Chambers concluded that sounds must have typical "speechlike" properties extracted at an early stage of processing in order to act as suffixes. In this article we use the suffix effect to investigate the conditions under which a sound is treated by the acoustic system as speechlike. On the basis of our findings we then perform other studies that reaffirm the essentially precategorical nature of the memory source termed PAS by Crowder and Morton. In Experiments 1-13 we demonstrate the complex basis on which sounds are classified. Our experiments show that a completely regular sound, in which a single pitch pulse from a naturally spoken vowel was repeatedly reproduced, still produced a substantial suffix effect. In addition a natural sound had to be quite severely filtered before the suffix effect began to vanish. However, a combination of regularity and filtering proved very effective, the two dimensions dramatically interacting in neutralizing the effect of the sound as a suffix. In two further experiments (14 and 15) we show that the classification parameters can be shifted by changing the acoustic properties of the stimulus list. However, forcing the subjects to make a linguistic classification of suffix sounds did not lead to any changes in their potency as suffixes. The classification of sounds, and thus the suffix effect, is an acoustic question, not a subjective one. The distinction between subjective and acoustic influences was further demonstrated when subjects rated a variety of sounds for their naturalness and for their similarity to the original suffix (Experiments 17-22). These measures showed themselves sensitive to the filtering operations we performed but, unlike measures of suffix effectiveness, were insensitive to regularity. Another suffix that produced a full suffix effect was shown to be rated as very nonspeechlike. Contrary to recent claims, these results reinforce our view of a distinction between central, subjectively controllable factors and a strong precategorical effect that is automatic in action and is based on the decision of whether a sound is speechlike.

Gestalt Theory, Insight, and Past Experience: Reply to Dominowski

Abstract: The present article addresses four important issues raised by Dominowski in his comments on our earlier article. First, we present evidence that our characterization of Gestalt theory is the view accepted by present-day psychologists and is also the view espoused by the Gestalt psychologists themselves. Second, we consider Dominowski's argument that the facilitation brought about by hints in our experiments as, in reality, support for Gestalt theory. Closer examination of the claims of Gestalt theory does not support Dominowski's interpretation of the data from our earlier article. Third, we examine in more detail our alternative interpretation of the data from our experiments. Fourth, we examine the roles proposed by Dominowski for the terms fixation and insight in psychological theory. In his comments on our earlier article (Weisberg & Alba, 1981), Dominowski (1981) raises a number of points, which, if correct, would seriously dilute the importance of our findings. In the present paper, we consider four issues raised by Dominowski. First, Dominowski argues that our earlier paper presents a mistaken characterization of Gestalt theory. Second, he questions whether the data concerning facilitation through hints in reality support Gestalt theory, contrary to our conclusions. Third, Dominowski argues that our explanation of our results is not very helpful. Fourth, he argues that we were being rash in suggesting that the terms insight and fixation be dropped from explanations of problem solving. Gestalt Theory Dominowski argues that our characterization of the Gestalt theory of problem solving is not accurate, and presents several quotes to support his claim. Two points should be made in response. First, and perhaps most important, the view we examine in our first paper concerning sudden and direct solutions to problems is the interpretation of Gestalt theory accepted by most present-day psychologists, which we briefly allude to in that

Mapping the visual field in mental imagery.

Abstract: We describe a simple psychophysical technique for measuring the size and shape of visual fields in mental imagery, and use this technique to compare fields in imagery and perception within which bar gratings of various spatial frequencies can be resolved. The first experiment demonstrates that the size of fields of resolution obtained when bar gratings are imagined decreases with increasing spatial frequency of the gratings, in the same way that the size of fields obtained when the gratings are actually observed decreases. This experiment also shows that imagery and perceptual fields are very similar in shape, both being elongated horizontally and extending farther below the point to which one's gaze is directed than above. The second experiment shows that experimental subjects are not able to anticipate the more subtle characteristics of these fields, such as the precise rate at which field size decreases with increasing spatial frequency--characteristics that most clearly reveal the very close correspondence between the imagery and perceptual fields. The third experiment shows that the size of the imagery fields can serve to discriminate between vivid and nonvivid imagers when the task of imagining the gratings is made sufficiently difficult. We interpret these findings as evidence that visual imagery involves the activation of mechanisms in the visual system that are specifically designed to process information about spatial frequency. In particular, we claim that constraints that these mechanisms impose on the resolution of high spatial frequencies in perception are also imposed in mental imagery, restricting how well fine details of an object can be imagined. We then discuss implications of these findings for theories about spatial-frequency analysis in vision and for the general issue of the functional value of mental imagery.

Decision Making With Texts: Information Analysis and Schema Acquisition

Abstract: SUMMARY While making decisions in a semantically rich natural situation, people encounter information, such as in texts, that is often massive and at the same time imprecise. Yet the desired information is extracted and decisions are made. In an attempt to study the characteristics of performance in such a situation, we created a laboratory analogue of the stock market. Subjects acting as stockbrokers acquired a conjunctive decision rule for predicting the market performance of a fictitious stock. After receiving suitable training, subjects read 20 "quarterly reports" containing information about six market information categories, of which only two were relevant to correct decisions. In each trial, subjects recorded their hypotheses about the categories in the the decision rule. Feedback was given following each decision, and the subjects were able to reread each text in order to decide if and how to modify their hypothesis about the rule. On some trials, following the decisions, the subjects were asked to free recall the texts they had just read. Decision performance distinguished between learners (subjects who discovered the decision rule) and nonlearners. The characteristics of hypothesis-selection behavior were similar to those observed in simpler concept-learning problems. Learners displayed a more global approach to the problem, were more sensitive to the given feedback, and utilized the available information more effectively than nonlearners. The category-recall patterns reflected the observed hypothesis-selection and decision behavior and the subjects' overall category-identification strategies. These data were congruent with a model of text comprehension, a result suggesting an equivalence between some of the comprehension and the hypothesis-selection operators. Effective decision in this task was viewed as the ability to acquire an appropriate control schema to guide the comprehension and the analysis of complex, often unreliable, text inputs.

Matching performance and the similarity structure of the stimulus set.

Abstract: To compare two general approaches toward understanding how objects are classified, this article explores performance in a series of studies that required matching visually presented letters. One general approach has stressed the analysis of details or elements of the input pattern. The other approach has focused on the relationships between the various elements and objects that the observer might expect to occur in the task. In empirical support of the first approach, many researchers have observed that the time it takes a subject to report that two visually presented letters have the same name is less when these letters are physically identical (e.g., A-A) than when they are physically different (e.g., A-a). This relative ease of matching physically identical letters has been attributed to a visual process that matches the letters on the basis of their physical characteristics. In support of the second approach, the studies in this article replicate this finding, but only for data averaged across letter parts. The data from individual letter pairs do not reflect this temporal hierarchy. Individual letter performance for an entire set of letters has not previously been reported, and the importance of analyzing fine structure in data is stressed. It is shown that physical identity matches can be reliably faster or slower than name identity matches. The similarity structure of the total stimulus set reliably predicts which result will occur. Within the limits of the variables studied, this conclusion is shown to be independent of the criterion for the type of match the subject is asked to make (physical identity or name identity) and of the temporal and physical separation of the letters. The readiness with which the presented stimuli can be discriminated from other members of the stimulus set controls performance. For example, as Experiment 1 shows, it is easy or difficult to report o-o as "same" depending on what other letters are used in the task. Lockhead's holistic-discriminability model provides a framework for interpreting these demonstrations that matching performance does not depend only on the stimuli physically present. Performance depends on the similarity or discriminability between the presented stimuli and other stimuli the observers know might be presented.

Does helplessness cause depression, or do only depressed people become helpless? Comment on Alloy and Abramson.

Abstract: Alloy and Abramson reported that depressed people are accurate at assessing response-outcome contingencies, whereas normal people display various distortions. It is argued that such a finding causes problems for a learned helplessness theory of depression, because it suggests that people can only detect some of the conditions necessary for producing helplessness after they are already depressed. The presumed causal relation between helplessness and depression may be strengthened if one assumes that helplessness prevents the development of active hypothesis-testing strategies that would otherwise produced biased assessments of contingency.

Cortical alpha rhythm, biofeedback, and the determinants of subjective state.

Abstract: A critical assumption in the rationale for the clinical application of voluntary control over central nervous system (CNS) activity is that there exists a direct relationship between specific CNS activities and specific subjective mood states. The experiment reported here was based on the idea that a joint manipulation of both cognitive and physiological (i.e., alpha electroencephalographic [EEG]) variables would provide information required for an explication of the processes involved in subjective mood change. Three main variables were considered in the present experiment. First, the instructions were designed to induce a "set" or expectations for either positive or negative changes in subjective mood. Second, the type of feedback (alpha or not alpha) was varied. Those in the not-alpha feedback condition received feedback contingent on the absence of alpha activity, whereas those in the alpha feedback condition received feedback contingent on the presence of alpha activity. Third, an estimate of each individual's baseline alpha density was obtained, and on this basis subjects were classified as high-baseline or low-baseline subjects. Baseline alpha density, alpha density during training, and subjective mood were all considered as continuous variables. The results of the present study indicate that biofeedback of the cortical alpha rhythm is neither a sufficient nor a necessary condition for changes in subjective mood. In addition, the type of instructions designed to set subjects for positive or negative alterations in subjective states is predictive of changes in subjective state reported during alpha biofeedback training as well as of success at controlling and changing EEG during feedback training. The data presented here permit a direct examination of the actual relationship of EEG changes to changes in subjective mood state. Similar shifts in subjective mood state can be obtained with either increases or decreases in alpha activity. Further, both positive and negative subjective experiences can be associated with increases in alpha activity.

Limited Capacity Theories and the Notion of Automaticity: Reply to Lucas and Bub

Abstract: Lucas and Bub argued that automatic should be thought of as meaning something similar to "outside of awareness." The argument they built around this definition does not bear on the existence of a limited capacity central processor. Moreover, the definition itself raises questions the resolution of which would involve systematic introspection, an experimental technique that was tried and abandoned.

Operant conditioning and discrimination of alpha: some methodological limitations inherent in response-discrimination experiments.

Abstract: Studies on the operant conditioning of central nervous system activity have produced results interpreted as demonstrating that responses, certain properties of responses, or response-produced stimuli can function as discriminative stimuli. It is assumed that the feedback stimulus in biofeedback makes the subject aware of the internal response and that by becoming aware of the response, the subject can acquire voluntary control over it. In this context, awareness is operationally defined as the ability to use the response as a discriminative stimulus. Since direct evidence for the assumed relationship between control and discrimination is lacking, an attempt was made to test the hypothesis that discrimination of a response automatically leads to control over that response. The discriminative stimuli were the presence and absence of occipital alpha electroencephalograph (EEG) activity. Data from two experiments are reported. The first study, employing naive subjects, was designed to answer the following questions: (a) Since pilot data indicated that subjects seemed to match their responses to the more probable type of trial, would increases in the probability of a correct response result when the probabilities of alpha and nonalpha trials were held near .50? (b) If correct responding does increase, would performance of these subjects in an alpha feedback task be enhanced relative to that of subjects not previously given discrimination training? and (c) If subjects could not learn the discrimination task, would feedback training enhance their performance in a subsequent discrimination task? Results from this study indicate that holding the probabilities of alpha and nonalpha discrimination trials near .50 results in an absence of learning curves, but leaves open the possibility that sophisticated subjects are capable of discriminating alpha and nonalpha activity. The second study deals with two questions: (a) Can sophisticated subjects learn to discriminate occipital alpha activity from nonalpha activity? and (b) Does the procedure of providing subjects with salient stimuli, contingent on the presence and absence of alpha activity, establish stimulus control of the presence and absence of alpha activity? Results indicate that it is not possible to conclude that subjects can learn to discriminate alpha and nonalpha activity. However, learning to increase percent-time nonalpha or decrease percent-time alpha with respect to baseline levels by means of EEG-contingent stimulation provides subjects with the ability to suppress percent-time alpha in the absence of feedback. Information gained in both studies through subject interviews indicates that subjects most often acquired their control of alpha activity during feedback by a specific strategy and then used the strategy during the stimulus-control tests.