Part I. Experimental Studies: 2. Experiment in psychology 3. Experiments on perceiving III Experiments on imaging 4-8. Experiments on remembering: (a) The method of description (b) The method of repeated reproduction (c) The method of picture writing (d) The method of serial reproduction (e) The method of serial reproduction picture material 9. Perceiving, recognizing, remembering 10. A theory of remembering 11. Images and their functions 12. Meaning Part II. Remembering as a Study in Social Psychology: 13. Social psychology 14. Social psychology and the matter of recall 15. Social psychology and the manner of recall 16. Conventionalism 17. The notion of a collective unconscious 18. The basis of social recall 19. A summary and some conclusions.

Remembering. A Study in Experimental and Social Psychology, Cambridge (University Press) 1964.

The power of feedback.

What Video Games Have to Teach Us about Learning and Literacy

It has been clear for almost two decades that cortical representations in adult animals are not fixed entities, but rather, are dynamic and are continuously modified by experience. The cortex can preferentially allocate area to represent the particular peripheral input sources that are proportionally most used. Alterations in cortical representations appear to underlie learning tasks dependent on the use of the behaviorally important peripheral inputs that they represent. The rules governing this cortical representational plasticity following manipulations of inputs, including learning, are increasingly well understood. In parallel with developments in the field of cortical map plasticity, studies of synaptic plasticity have characterized specific elementary forms of plasticity, including associative long-term potentiation and long-term depression of excitatory postsynaptic potentials. Investigators have made many important strides toward understanding the molecular underpinnings of these fundamental plasticity processes and toward defining the learning rules that govern their induction. The fields of cortical synaptic plasticity and cortical map plasticity have been implicitly linked by the hypothesis that synaptic plasticity underlies cortical map reorganization. Recent experimental and theoretical work has provided increasingly stronger support for this hypothesis. The goal of the current paper is to review the fields of both synaptic and cortical map plasticity with an emphasis on the work that attempts to unite both fields. A second objective is to highlight the gaps in our understanding of synaptic and cellular mechanisms underlying cortical representational plasticity.

/pdf/cortical-plasticity-from-synapses-to-maps-2j9eoi9428.pdf

CORTICAL PLASTICITY: From Synapses to Maps

Convergence of inputs from different sensory modalities onto individual neurons is a phenomenon that occurs widely throughout the brain at many phyletic levels and appears to represent a basic neural mechanism by which an organism integrates complex environmental stimuli. In the present study, neurons in the superior colliculus (SC) were used as a model to examine how single neurons deal with simultaneous cues from different sensory modalities (e.g., visual, auditory, somatosensory). The functional result of multisensory convergence on an individual cell was determined by comparing the responses evoked from it by a combined-modality (multimodal) stimulus with those elicited by each (unimodal) component of that stimulus presented alone. Superior colliculus cells exhibited profound changes in their activity when individual sensory stimuli were combined. These "multisensory interactions" were found to be widespread among deep laminae cells and fell into one of two functional categories: response enhancement, characterized by a significant increase in the number of discharges evoked; and response depression, characterized by a significant decrease in the discharges elicited. Multisensory response interactions most often reflected a multiplicative, rather than summative, change in activity. Their absolute magnitude varied from cell to cell and, when stimulus conditions were altered, within the same cell. However, the percentage change of enhanced interactions was generally inversely related to the vigor of the responses that could be evoked by presenting each unimodal stimulus alone and suggest that the potential for response amplification was greatest when responses evoked by individual stimuli were weakest. The majority of cells exhibiting multi-sensory characteristics were demonstrated to have descending efferent projections and thus had access to premotor and motor areas of the brain stem and spinal cord involved in SC-mediated attentive and orientation behaviors. These data show that multisensory convergence provides the descending efferent cells of the SC with a dynamic response character. The responses of these cells and the SC-mediated behaviors that they underlie need not be immutably tied to the presence of any single stimulus, but can vary in response to the particular complex of stimuli present in the environment at any given moment.

Visual, auditory, and somatosensory convergence on cells in superior colliculus results in multisensory integration

We examined the effect of unilateral restricted cochlear lesions in adult cats on the topographic representations ("maps") of the lesioned and unlesioned cochleas in the primary auditory cortex (AI) contralateral to the lesioned cochlea. Frequency (tonotopic) maps were derived by conventional multineuron mapping procedures in anesthetized animals. In confirmation of a study in adult guinea pigs (Robertson and Irvine [1989] J. Comp. Neurol. 282:456-471), we found that 2-11 months after the unilateral cochlear lesion the map of the lesioned cochlea in the contralateral AI was altered so that the AI region in which frequencies with lesion-induced elevations in cochlear neural sensitivity would have been represented was occupied by an enlarged representation of lesion-edge frequencies (i.e., frequencies adjacent to those with elevated cochlear neural sensitivity). Along the tonotopic axis of AI the total representation of lesion-edge frequencies could extend up to approximately 2.6 mm rostal to the area of normal representation of these frequencies. There was no topographic order within this enlarged representation. Examination of threshold sensitivity at the characteristic frequency (CF, frequency to which the neurons were most sensitive) in the reorganized regions of the map of the lesioned cochlea established that the changes in the map reflected a plastic reorganization rather than simply reflecting the residue of prelesion input. In contrast to the change in the map of the lesioned contralateral cochlea, the map of the unlesioned ipsilateral cochlea did not differ from those in normal animals. Thus, in contrast to the normal very good congruency between ipsilateral and contralateral AI maps, in the lesioned animals ipsilateral and contralateral maps differed in the region of AI in which there had been a reorganization of the map of the lesioned cochlea. Outside the region of contralateral map reorganization, ipsilateral and contralateral AI maps remained congruent within normal limits. The difference between the two maps in the region of contralateral map reorganization suggested, in light of the physiology of binaural interactions in the auditory pathway, that the cortical reorganization reflected subcortical changes. Finally, response properties of neuronal clusters within the reorganized map of the lesioned cochlea were compared to normative data with respect to threshold sensitivity at CF, the size of frequency "response areas," and response latencies. In the majority of cases, CF thresholds were similar to normative data. The frequency "response areas" were slightly less sharply tuned than normal, but not significantly. Response latencies were significantly shorter than normal in three animals and significantly longer in one animal.

Effect of unilateral partial cochlear lesions in adult cats on the representation of lesioned and unlesioned cochleas in primary auditory cortex

https://isiarticles.com/bundles/Article/pre/pdf/32251.pdf

The effects of personality traits, self-esteem, loneliness, and narcissism on Facebook use among university students

1. The auditory responses of 207 single neurons in the intermediate and deep layers of the superior colliculus (SC) of barbiturate -or chloralose-anesthetized cats were recorded extracellularly. Sealed stimulating systems incorporating calibrated probe microphone assemblies were employed to present tone- and noise-burst stimuli. 2. All acoustically activated neurons responded with onset responses to noise bursts. Of those neurons also tested with tonal stimuli, approximately 30% were unresponsive over the frequency range tested (0.1-40 kHz), while the others had higher thresholds to tones than to noise. 3. Details of frequency responsiveness were obtained for 55 neurons; 21 were broadly tuned, while 34 were sharply tuned with clearly defined characteristic frequencies (CFs). All sharply tuned neurons had CFs greater than or equal to 10 kHz. 4. The majority of neurons (81%) responded with latencies in the range 8-20 ms; only 11% of neurons had latencies greater than 30 ms. 5. Binaural response properties were examined for 165 neurons. The great majority (79%) received monaural excitatory input only from the contralateral ear (EO). However, most EO cells were binaurally influenced, the contralateral response being either inhibited (EO/I; 96 of 131 units) or facilitated (EO/F; 33 of 131 units) by simultaneous ipsilateral stimulation. Small subgroups were monaurally excited by either ear (EE cells; 8%) or were unresponsive monaurally but responded strongly to binaural stimulation (OO/F cells; 7%). 6. EO/I, EO/F, and OO/F neurons showed characteristic forms of sensitivity to interaural intensity differences (IIDs). The IID functions of EO/I neurons would be expected to produce large contralateral spatial receptive fields with clearly defined medial borders, such as have been described in studies of deep SC neurons employing free-field stimuli. 7. Preliminary evidence suggests a possible topographic organization of IID sensitivity in deep SC, such that the steeply sloping portion of the function (corresponding to the medial edge of the receptive field) is shifted laterally for EO/I neurons located more caudally in the nucleus. 8. The auditory properties of deep SC neurons are compared with previous reports and implications for the organization of auditory input are considered. The binaural properties and auditory spatial fields of deep SC neurons suggest that any representation of auditory space in this structure is unlikely to be based on restricted spatial fields.

Auditory response properties of neurons in deep layers of cat superior colliculus.

Sensitivity to interaural intensity difference (IID) was examined for 103 neurons in the deep layers of superior colliculus (SC) in ketamine barbiturate-anesthetized cats. Noise stimuli were presen...

Topographic organization of interaural intensity difference sensitivity in deep layers of cat superior colliculus: implications for auditory spatial representation

Although there is evidence that academically successful students are engaged with their studies, it has proved difficult to define student engagement clearly. Student engagement is commonly construed as having two dimensions, social and academic. The rapid adoption of social media and digital technologies has ensured increasing interest in using them for improving student engagement. This paper examines Facebook usage among a first year psychology student cohort and reports that although the majority of students (94%) had Facebook accounts and spent an average of one hour per day on Facebook, usage was found to be predominantly social. Personality factors influenced usage patterns, with more conscientious students tending to use Facebook less than less conscientious students. This paper argues that, rather than promoting social engagement in a way that might increase academic engagement, it appears that Facebook is more likely to operate as a distracting influence.

/pdf/facebook-in-higher-education-promotes-social-but-not-46v588b4jb.pdf

Lisa Wise

Papers

Effect of unilateral partial cochlear lesions in adult cats on the representation of lesioned and unlesioned cochleas in primary auditory cortex

The effects of personality traits, self-esteem, loneliness, and narcissism on Facebook use among university students

Auditory response properties of neurons in deep layers of cat superior colliculus.

Topographic organization of interaural intensity difference sensitivity in deep layers of cat superior colliculus: implications for auditory spatial representation

Facebook in higher education promotes social but not academic engagement.