Showing papers in "Attention Perception & Psychophysics in 1975"

The span of the effective stimulus during a fixation in reading.

Abstract: A computer-based eye-movement controlled, display system was developed for the study of perceptual processes in reading. A study was conducted to identify the region from which skilled readers pick up various types of visual information during a fixation while reading. This study involved making display changes, based on eye position, in the text pattern as the subject was in the act of reading from it, and then examining the effects these changes produced on eye behavior. The results indicated that the subjects acquired word-length pattern information at least 12 to 15 character positions to the right of the fixation point, and that this information primarily influenced saccade lengths. Specific letter- and word-shape information were acquired no further than 10 character positions to the right of the fixation point.

An effect of linguistic experience: The discrimination of (r) and (l) by native speakers of Japanese and English.

Abstract: To test the effect of linguistic experience on the perception of a cue that is known to be effective in distinguishing between [r] and [l] in English, 21 Japanese and 39 American adults were tested on discrimination of a set of synthetic speech-like stimuli. The 13 “speech” stimuli in this set varied in the initial stationary frequency of the third formant (F3) and its subsequent transition into the vowel over a range sufficient to produce the perception of [r a] and [l a] for American subjects and to produce [r a] (which is not in phonemic contrast to [l a ]) for Japanese subjects. Discrimination tests of a comparable set of stimuli consisting of the isolated F3 components provided a “nonspeech” control. For Americans, the discrimination of the speech stimuli was nearly categorical, i.e., comparison pairs which were identified as different phonemes were discriminated with high accuracy, while pairs which were identified as the same phoneme were discriminated relatively poorly. In comparison, discrimination of speech stimuli by Japanese subjects was only slightly better than chance for all comparison pairs. Performance on nonspeech stimuli, however, was virtually identical for Japanese and American subjects; both groups showed highly accurate discrimination of all comparison pairs. These results suggest that the effect of linguistic experience is specific to perception in the “speech mode.”

Cognitive processing and time perception

Abstract: When a visual field is presented for 40 or 80 msec and a subject is asked to judge the duration of the stimulus, judged duration is found to be less when the field is blank than when the field contains three letters, but is the same whether the three letters form a word or not. The perceived difference between “filled” and “blank” fields increases when the subject is required to memorize the presented letters. These data are consistent with a theory which assumes,inter alia, that a stimulus is analyzed by a visual information processor and a timer, that attention is shared between these processors, and that temporal judgments are based on the output of both processors.

Discrimination of short temporal intervals: A comparison of two models

Abstract: Duration-discrimination data from an experiment using empty auditory intervals in a two-alternative forced-choice paradigm are presented The observed functional relationship between standard deviation of the psychometric density function and stimulus duration is shown to be fit significantly better by a Weber’s law model of duration discrimination than by Creelman’s counter model Both models fail to predict the rapid rise in the Weber fraction observed for durations longer than about 2 sec However, the Weber’s law model, based on a generalization of Weber’s law, accurately predicts the initial drop in the Weber fraction for very short durations and the observed constancy of the Weber fraction for durations up to 2 sec

Auditory and phonetic coding of the cues for speech: Discrimination of the [r-l] distinction by young infants

Abstract: Infants, 2 and 3 months of age, were found to discriminte stimuli along the acoustic continuum underlying the phonetic contrast [r] vs. [l] in a nearly categorical manner. For an approximately equal acoustic difference, discrimination, as measured by recovery from satiation or familiarization, was reliably better when the two stimuli were exemplars of different phonetic categories than when they were acoustic variations of the same phonetic category. Discrimination of the same acoustic information presented in a nonspeech mode was found to be continuous, that is, determined by acoustic rather than phonetic characteristics of the stimuli. The findings were discussed with reference to the nature of the mechanisms that may determine the processing of complex acoustic signals in young infants and with reference to the role of linguistic experience on the development of speech perception at the phonetic level.

Intensity and reverberation as factors in the auditory perception of egocentric distance

Abstract: Both auditory intensity and reverberation have previously been shown to be sufficient to produce systematically varying judgments of perceived distance when several values of the variable are presented repeatedly to the same observer. Such studies do not, however, indicate clearly whether these cues are functioning in an absolute or in a relative manner. An absolute cue to auditory distance would require that two groups presented with different values of the variable in question should report different values of perceived distance. Two experiments are reported in which intensity variation and reverberation are examined. The results showed that auditory intensity differences over a range of 20 dB did not serve as an absolute cue to auditory distance, but could serve as a strong cue to changes in such distance. A comparison of data obtained in a normally reverberatory setting (Experiment 1) and an anechoic chamber (Experiment 2) indicated that the state of reverberation could serve as an absolute cue, with greater reverberation being associated with greater perceived distances. Some of the results were discussed in terms of the possibility that the specific distance tendency (a concept developed to handle some phenomena in visual space perception) might have applicability to the study of auditory perceived distance as well.

Misperception of exponential growth

Abstract: Exponential growth in numerical series and graphs is grossly underestimated in an intuitive extrapolation task. Subjects’ extrapolations are well described by a model with two parameters only: one for underestimation of the nonlinear growth, the other for linear compensation. The size of the effect is considerable; it is not unusual that two-thirds of the subjects produce estimates below 10% of the normative value. The effect increases with the exponent of the stimulus series, and with addition of a constant to the stimulus series. Neither special instructions about the nature of exponential growth nor daily experience with growth processes enhanced the extrapolations.

Saccadic localization of visual targets by the very young human infant

Abstract: The direction, latency, and form of the 1- and 2-month-old human infant’s saccadic eye movements toward peripheral targets were investigated. Infants of both ages reliably executed a directionally appropriate first saccade toward a peripheral target introduced as far as 30 deg from the line of sight along the horizontal and both diagonal axes, but only to 10 deg along the vertical axis. The presence of a second target in the central visual field reduced the probability of peripheral target localization. A significant inverse relation was found between target distance from the line of sight and probability of initiating a directionally appropriate saccade. Electro-oculography revealed that latency to first saccade, although highly variable, was less than 500 msec on a significant proportion of trials. Unlike the adult, the first saccade to target was grossly hypometric and was followed by one or more saccades of approximately equal amplitude to the first.

Influence of foveal load on the functional visual field

Abstract: The functional visual field defined in terms of a discrimination task of a target presented peripherally among ambiguous background patterns was investigated for various foveal loads which were to be recognized at the central retina. Foveal loads were numbers, letters, place names, traffic signs, and other figures to simulate commonplace situations for foveal information processing, and grouped into three in order of recognition difficulty based on daily experience. Boundaries of the functional visual field were obtained for simple fixation and for certain foveal loads. Comparison of these boundaries clearly showed shrinkage of the functional visual field size with the foveal loads of greater recognition difficulty.

Tactile roughness of grooved surfaces: A model and the effect of friction

Abstract: Previous experimental data on the roughness of grooved aluminum tiles provide a data base against which to test theories of roughness perception. A model based on the static deformation of the skin touching the stimulus tile is developed, and 11 parameters of the deformation are individually compared with the experimental data. All parameters were tested first in an approximate way, and then the better parameters were recalculated in a more exact manner. Three parameters, the depth to which the finger penetrates the groove, the cross-sectional area of the finger within the groove, and the cross-sectional area of the deviation of the skin from its resting position, all predict the roughness well as a function of finger force and groove width. The last of the three predicts roughness best as a function of land width, and is tentatively preferred as “the stimulus for roughness.” All predictions from the static model indicate that variation of the coefficient of friction between skin and tile should have little or no effect. This counterintuitive prediction was confirmed by an experiment.

Foreground and background in dynamic spatial orientation

Abstract: The dependency of visually induced self-motion sensation upon the density of moving contrasts as well as upon additional stationary contrasts in the foreground or background was investigated. Using two different optokinetic stimuli, a disk rotating in the frontoparallel plane, and the projection of horizontally moving stripes onto a cylindrical screen, it was found that: (1) visually induced self-motion depends upon the density of moving contrasts randomly distributed within the visual field and, with a single contrast area of 1/4 %, is saturated when about 30% of the visual field is moving; (2) additional stationary contrasts inhibit visually induced serf-motion, proportional to their density; and (3) the location in depth of the stationary contrasts has a significant effect upon this inhibition. Their effect is considerable when located in the background of the moving stimuli but weak when appearing in the foreground. It is concluded that dynamic visual spatial orientation relies mainly on information from the seen periphery, both retinal and depth.

Stochastic properties of binocular rivalry alternations

Abstract: Previous researches have demonstrated that the successive phase durations in binocular rivalry are independent. These findings are confirmed and extended to chromatic stimuli. The nature of the function that is shown to describe the distribution of the dominance phase durations is consistent with the independence of successive phases and suggests that a parallel may exist between binocular rivalry and the perceptual reversal of ambiguous figures.

Rated preference for musical compositions as it relates to complexity and exposure frequency

Abstract: Subjects heard four piano compositions that were constructed to represent differing degrees of complexity, as defined by their chordal and rhythmic properties and corroborated by subjects’ complexity ratings. In line with the predictions of an optimal complexity model of musical preference, judged liking for the compositions was a unimodal function of their complexity. After each composition was rated for liking, one of the four compositions was presented and rated an additional 16 times. Also congruent with an optimal complexity model was the finding that the affective consequences of repeated exposure varied depending upon whether the repeatedly exposed composition was more or less complex than the subject’s preferred complexity level. The latter finding suggests that repeated exposure effects are a function of both situational and individual factors.

The “ventriloquist effect”: Visual dominance or response bias?

Abstract: The interaction between vision and audition was investigated using a signal detection method. A light and tone were presented either in the same location or in different locations along the horizontal plane, and the subjects responded with same-different judgments of stimulus location. Three modes of stimulus presentation were used: simultaneous presentation of the light and tone, tone first, and light first. For the latter two conditions, the interstimulus interval was either 0.7 or 2.0 sec. A statistical decision model was developed which distinguished between the perceptual and decision processes. The results analyzed within the framework of this model suggested that the apparent interaction between vision and audition is due to shifts in decision criteria rather than perceptual change.

An examination of relationships between the pleasantness, intensity, and concentration of 10 odorous stimuli

Abstract: Relationships between physical concentration, perceived pleasantness, and perceived intensity were established by the method of magnitude estimation for 10 diverse chemical stimuli. Estimates of pleasantness significantly correlated with those of intensity for seven of the compounds examined. In all cases, the relationships between perceived intensity and physical concentration were described relatively well by power functions. However, this was not true for the pleasantness/concentration relationships. Intensity exponents correlated moderately with a number of common physicochemical parameters. Large differences were present between individual observer’s ratings of the perceived pleasantness of the odorants. These data indicate that the perceived pleasantness of some odorants may be systematically related to their perceived intensity, but do not support the notion that these dimensions are equivalent.

The development of visually guided reaching

Abstract: This investigation measured the accuracy of reaching in infants wearing 30-diopter prisms. Infants varied in age from 4 to 10 months. Although accuracy was barely affected, the reach trajectories indicated that infants switched from a miss path to a hit path in midcourse. There was some evidence to support the view that visually directed reaching was operative in the youngest infants and that it improved with age.

Ear asymmetry in reaction time to musical sounds

Abstract: Dichotic pairs of musical sounds were presented to 16 right-handed subjects, who were instructed to depress a reaction-time (RT) button when a target sound occurred in either ear. Four blocks of 36 trials were presented. During the first block, RTs to left-ear targets were significantly faster than those to right-ear targets. There were no significant ear differences during the second, third, or fourth blocks. Possible explanations for the limited duration of the left-ear advantage, and its implications for models proposed to explain the basis of RT asymmetries, are discussed.

Taste of nutrients: Amino acids, vitamins, and fatty acids

Abstract: Multidimensional scaling techniques were used to determine the range in taste of nutrients for human subjects. The nutrients tested (amino acids, vitamins, and fatty acids) span the traditional sweet, sour, salty. and bitter gustatory quality range. The results also suggest that alkaline, sulfurous, and fatty qualities exist as well; the possibility that these three quality groupings are due to olfactory or tactile rather than gustatory input is discussed. The traditional literature in gustation (Henning, 1916; von Skrarnlik, 1926) assumes that all gustatory

The relation between size and apparent heaviness

Abstract: A formula for the size-weight illusion was derived from the Stevens and Rubin (1970) finding that heaviness functions form a family of power functions that converge at a common point in the vicinity of the heaviest weight that can be lifted. Magnitude estimations of the apparent heaviness of 42 plastic cylinders varying in size and weight were obtained from 20 subjects, who were allowed to use both hands to lift the weights. It was predicted that this would increase the maximum weight that could be lifted, which would, in turn, enhance the magnitude of the illusion (the dependence of heaviness on size). The results supported this and other predictions of the model concerning the dependence of the illusion on weight as well as volume.

An investigation of categorical speech discrimination by rhesus monkeys

Abstract: The categorical discrimination of synthetic human speech sounds by rhesus macaques was examined using the cardiac component of the orienting response. A within-category change which consisted of stimuli differing acoustically in the onset of F2 and F3 transitions, but which are identified by humans as belonging to thesame phonetic category, were responded to differently from a no-change control condition. Stimuli which differed by the same amount in the onset of F2 and F3 transitions, but which human observers identify as belonging toseparate phonetic categories, were differentiated to an even greater degree than the within-category stimuli. The results provide ambiguous data for an articulatory model of human speech perception and are interpreted instead in terms of a feature-detector model of auditory perception.

Grouping by proximity: Selective attention measures

Abstract: The role of element proximity in perceptual grouping was examined in tasks requiring speeded discrimination of two-element visual patterns. Grouping of two elements was defined as the failure of attention to be focused on one element selectively in filtering tasks where only that one element was relevant to the discrimination. Failure of selective attention was measured by the degree of interference caused by variation of the irrelevant element. Grouping was shown to diminish monotonically as the spacing between two elements was increased. At a given spacing, grouping could be reduced or eliminated by the introduction of a third element into the stimulus field, presumably because the addition of this element triggered a reorganization of the perceptual field into a new grouping structure. Grouping appeared to facilitate performance on condensation tasks requiring distributed attention, to the degree that the condensation tasks were actually easier than the filtering tasks at close proximities. Paradoxically, for some tasks, moving an irrelevant element away from a relevant one actually impaired performance, suggesting that paying attention to irrelevant information could be beneficial. This result, if generalizable, suggests that grouping be conceptualized not as an automatic process under preattentive control but as an optional process under strategic control.

On the duality of simultaneous time and size perception

Abstract: When subjects are asked to judge the duration and size of visually presented circles that vary in duration and size, perceived duration is directly related to stimulus size and perceived size is, in most cases, directly related to stimulus duration. When subjects are asked to process time and size information simultaneously, their time judgments are the same as when only time processing is required, but their size judgments are less than when only size processing is required. These data are discussed within the context of an explicit model for the processing of size information, added to which is the assumption that time judgments are influenced by the time spent processing size information.

Perceptual aftereffects of sustained convergence

Abstract: It has been known for some time that maintaining the eyes in a state of vertical divergence induces a deviation in the fusion-free position of the two eyes that persists for some time after the inducing stimulation is withdrawn (Ellerbrock & Fry. 1941). Furthermore. to a certain extent. the degree to which the eyes can be made to diverge will vary with the direction in which the eyes were previously maintained. smaller deviations occurring when the eyes successively assume opposite directions (Ellerbrock & Fry. 1941). A similar aftereffect has been described which occurs when both eyes assume a common direction. e.g .. holding the direction of gaze to the left or right (Carr. 1910; Park. 1969). Thus the fusion reflex which is responsible for maintaining the state of vertical divergence is not necessary for the occurrence of the aftereffect. In both cases. conditions arc such that some subset of the six extraocular muscles is innervated and muscle tension is maintained for a short time period. The common aftereffect. in which the eyes are pulled in the direction consistent with prior muscle innervation, follows simply from the premise that the muscle innervation pattern continues beyond the point where either the innervation stimulus is removed (e.g., disparate images in the case of the fusion reflex) or where the volitional command to relax is given. Yet another class of muscle aftereffects exists. initially reported by Kohnstarnm (1915). that follow the same ru le. but have been applied typically to skeletal muscle and associated appendages. Perhaps the best known of these effects is the demonstration of the arm that rises. in the absence of any conscious direction. as an aftereffect of sustained pressure against a wall. On the basis of parsimony and in the absence of evidence to the contrary. there is justification for the classification of the three muscle aftereffects described above as members of a common set of phenomena whose determining condition is The research was supported in part by Grant MH 13006 from NIMH. The aid of Jean Ebenholtz in running Experiments VIII and IX and in data analysis is gratefully acknowledged.

Hemisphere differences in an auditory Stroop test

Abstract: In an auditory Stroop test, right-handed subjects were required to judge the pitch of the following stimuli: two pure tones, one at a high frequency and one at a low frequency; two congruent words, “high,” sung at the high frequency, and “low,” sung at the low frequency; and two noncongruent words, “high” at low frequency and “low” at high frequency. A sequence of these stimuli was presented monaurally first to one ear, and then to the other. The Stroop effect (the difference between mean RT to congruent words, and mean RT to noncongruent words) was larger for right ear (left hemisphere) presentation. The same experiment was repeated dichotically with a competing message presented to the opposite ear. Again, the Stroop effect was larger for the right ear, and the ear differences were slightly more marked. The result is interpreted as reflecting hemispheric specialization for linguistic and nonlinguistic processing and a model of Stroop conflict in which response competition varies with the relative availability of the conflicting response.

Eye-Movements During Search for Coded and Uncoded Targets

Abstract: Eye movements and search time of four subjects were studied as they searched for a target dial in a 4 х 4 array of dials which were differentiated by (1) color, (2) shape, (3) a combination of color and shape, or (4) were uncoded. Subjects did not exhibit a characteristic scanpath, and method of scanning did not relate to search time. Search time varied reliably among conditions; it was generally shortest in the color condition, followed by color shape, shape, and the uncoded condition. Subjects were capable of using both shape and color simultaneously. Search time was strongly associated with the average number of fixations required for target detection but not with other measures of eye movements. Fixation duration was a particularly inconsistent measure.

The role of regression and range effects in determination of the power function for electric shock

Abstract: A scale for the apparent intensity of electric shock applied to the forearm was derived from cross-modality matching functions relating noise level, number, and force of handgrip to both line length and shock. For each response mode, the effects of psychophysical regression were estimated from the line judgments and used to make adjustments in the corresponding shock judgments. For shocks ranging from (1.0 to 5.5 mA, combined estimates of subjective magnitude were found to grow as the 2.26 power of the stimulating current.

Presentation order effects in duration discrimination

Abstract: Three separate experiments indicate that the second of a pair of durations tends to be overestimated relative to the first. These negative time-order errors are discussed as reliable perceptual phenomena, not explainable in terms of simple response biases, criterion biases, assimilation, or fading traces.

Hierarchical stages in the processing of visual information

Abstract: Previous research had indicated that when subjects are instructed to report one of a number of visually displayed items, both the number and spacing of the presented material affect report accuracy and latency. The present experiment sought to determine the nature and temporal course of the interference provided by nonattended visual material. Subjects reaction times were measured for deciding which of two targets occupied the indicated position in one or eight element displays. Placing replicas of the target in nonindicated display positions was equivalent to presenting the target alone. Members of the opposite response set produced maximum interference, while encodable and unencodable noise elements not belonging to a response set produced an intermediate decrement. For all display types, presenting the indicator prior to display onset decreased reaction time. Dividing each of the display elements into two parts and presenting the parts asynchronously provided evidence that subjects were indifferent to the presence of complete forms for the first 50 msec. These results were interpreted as supporting the existence of a hiararchical sequence of stages consisting of a preattentive stage which segregates the input into objects and an attentive stage which is likened to a spatial scanner responsible for synthesizing the crude preattentive features into recognized forms. The concurrent operation of these stages provides for the redirection of attention when changes in the input are detected.

Treatments of bias in detection and recognition models: A review

Abstract: The review considers various proposals about the form of isobias curves and about the relation between bias and bias conditions (payoff, presentation probability, and instructions). Though the proposals differ sharply, none of them proves to be adequately supported by existing evidence. There has been a curious tendency to appeal to a priori arguments, to consider only a very restricted set of alternatives from among the published proposals, to contrast proposals at levels of performance where their predictions are minimally different, and to ignore existing evidence. The review tries to provide a solid basis for more adequate experimental work in the future.

The relationship between judgments of successiveness

Abstract: The purpose of the present set of experiments was to determine the nature of the relationship between judgments of successiveness and judgments of order. The relationship was examined in terms of models which assume that the perception of successiveness is sufficient for the perception of correct temporal order. It was demonstrated that successiveness and order judgments cannot be jointly explained by perceptual latency models which assume that both judgments are based on the same internal event. This is the case regardless of the form of the perceptual latency distribution, and for either a threshold or a nonthreshold decision process. On the other hand, performance on a successiveness discrimination task, an order discrimination task, and a task requiring both a successiveness and an order judgment on each trial is consistent with the predictions of the attention-switching model.