Proper Name Hypermnesia in an Autistic Subject

The case study of an autistic “savant” subject with person names hypermnesia is presented. NM's performance in memorizing person names is compared to that of normal controls, IQ-matched controls, and one overtrained control. The data show a selective hypermnesia for both the free recall of person names and the recognition of faces. Recall of common names and of biographical informations linked to faces is unremarkable. NM's hypermnesia is restricted to list learning as low performance is observed in face-name learning tasks. A comparison of the data with that of the overtrained control indicates that training is not responsible for NM's pattern of results. These findings, when combined with previous results involving proper names, demonstrate a double dissociation between proper names and other types of semantic and referential information. However, aspects of NM's performance pattern are more compatible with a network model of proper names than with a sequential model. We propose that the contextual regularity of proper names in ecological situations can be responsible for their high memorization by NM.     

Perceiving musical tension in long chord sequences

We attempted to predict perceived musical tension in longer chord sequences by hierarchic and sequential models based on Lerdahl and Jackendoff's and Lerdahl's cognitive theories and on Parncutt's sensory-psychoacoustical theory. Musicians and nonmusicians were asked to rate the perceived tension of chords which were drawn either from a piece composed for the study (Exp. 1) or from a Chopin Prelude (Exps. 2–4). In Exps. 3 and 4, several experimental manipulations were made to emphasize either the global or the local structure of the piece and to verify how these manipultions would affect the respective contribution of the models in the ratings. In all experiments, musical tension was only weakly influenced by global harmonic structure. Instead, it mainly seemed to be determined locally, by harmonic cadences. The hierarchic model of Lerdahl and Jackendoff provided the best fit to tension ratings, not because it accounted for global hierarchic effects, but because it captured the local effect of cadences. By reacting to these local structures, tension ratings fit quite well with a hierarchic model, even though the participants were relatively insensitive to the global structure of the pieces. As a main outcome, it is argued that musical events were perceived through a short perceptual window sliding from cadence to cadence along a sequence. Received: 24 March 1997 / Accepted: 10 May 1998     

The emergence of explicit knowledge during the early phase of learning in sequential reaction time tasks

Five experiments investigated the formation of explicit knowledge of a repeating sequence in a sequential reaction time task. Reliable explicit knowledge was obtained even though various conditions prevented the selective improvement of RTs (Exps. 1–4). This knowledge emerged early during training. Participants were able to recognize segments of the sequence (Exps. 3 and 4) or correctly assess the probabilities of transition of the target between successive locations (Exp. 5) after only two blocks of training trials. These findings rule out an interpretation of sequence learning that posits that explicit knowledge emerges from implicit knowledge during the course of training. Although these findings are compatible with a framework centered around the notion of dissociation between implicit and explicit knowledge, they are also consonant with a questioning of the usefulness of the concept of implicit knowledge.     

An exploration of the moderating effect of trait emotional intelligence on memory and attention in neutral and stressful conditions

Trait emotional intelligence (trait EI) refers to individual differences in the experience, perception, regulation, and utilization of emotions. Research has shown that trait EI moderated subjective and endocrine responses to both natural and laboratory stressors. This study explores, the cognitive processes underlying this effect, under the hypothesis that trait EI moderates the impact of stress on memory and/or attention. Results supported the hypothesis, but solely for the ‘regulation’ EI‐dimension (named self‐control or SC). In neutral conditions, high SC was characterized by an attentional focus to neutral material and a facilitated memory for positive events, whereas low SC was characterized by an attentional focus to emotional material (regardless of valence) and a facilitated memory for negative events. In stressful conditions, high SC individuals engaged attention to emotional material (regardless of valence) and recalled more negative events, while low SC individuals disengaged attention from emotional material and recalled more positive events.     

Speculations on the emergence of self-awareness in big-brained organisms: the roles of associative memory and learning, existential and religious questions, and the emergence of tautologies

This paper argues that self-awareness emerges in organisms whose brains have a sufficiently integrated, complex ability for associative learning and memory. Continual sensory input of information related to the organism leads to the formation of a set of associations that may be termed an organismal “self-image”. After providing the basic mechanistic basis for the emergence of an organismal self-image, this paper proceeds to go through a representative list of behaviors associated with self-awareness, and shows how associative memory and learning, combined with an organismal self-image, leads to the emergence of these various behaviors. This paper also discusses various tautologies that invariably emerge when discussing self-awareness. We continue with various speculations on manipulating self-awareness, and discuss how concepts from set and logic theory may provide a useful set of tools for understanding the emergence of higher cognitive functions in complex organisms.     

Rapid eye-fixation training without eyetracking

Maintenance of stable central eye fixation is crucial for a variety of behavioral, electrophysiological, and neuroimaging experiments. Naive observers in these experiments are not typically accustomed to fixating, either requiring the use of cumbersome and costly eyetracking or producing confounds in results. We devised a flicker display that produced an easily detectable visual phenomenon whenever the eyes moved. A few minutes of training using this display dramatically improved the accuracy of eye fixation while observers performed a demanding spatial attention cuing task. The same amount of training using control displays did not produce significant fixation improvements, and some observers consistently made eye movements to the peripheral attention cue, contaminating the cuing effect. Our results indicate that (1) eye fixation can be rapidly improved in naive observers by providing real-time feedback about eye movements, and (2) our simple flicker technique provides an easy and effective method for providing this feedback. S. Suzuki, satoru@northwestern.edu     

Dutch plural inflection: the exception that proves the analogy

We develop the view that inflection is driven partly by non-phonological analogy and that non-phonological information is of particular importance to the inflection of non-canonical roots, which in the view of [Marcus, G. F., Brinkmann, U., Clahsen, H., Wiese, R., & Pinker, S. (1995). German inflection: the exception that proves the rule. Cognitive Psychology, 29, 189-256.] are inflected by a symbolic rule process. We used the Dutch plural to evaluate these claims. An analysis of corpus data shows that a model using non-phonological information (orthography) produces significantly fewer errors on plurals of non-canonical Dutch nouns, in particular borrowings, than a model that includes only phonological information. Moreover, we show that a double default system, as proposed by Pinker [Pinker, S. (1999). Words and rules. London: Phoenix.], does not offer an advantage over the latter model. A second study, examining the use of orthography in an online plural production task, shows that, in Dutch, the chosen pseudoword plural is significantly affected by non-phonological information. A final simulation study confirms that these results are in line with a model of inflectional morphology that explains the inflection of non-canonical roots by non-phonological analogy instead of by a default rule process.     

Stress Sensitization and Adolescent Depressive Severity as a Function of Childhood Adversity: A Link to Anxiety Disorders

The goal of the present study was to determine whether exposure to adversity in childhood contributes to a differential threshold at which stressful life events provoke depressive reactions in adolescence. In addition, to address empirical and conceptual questions about stress effects, the moderating effect of anxiety disorder history was also explored. This examination was conducted in a sample of 816 children of depressed and nondepressed mothers, who were followed from birth to age 15. Information on adversities experienced in childhood was collected both from mothers during the first five years of their youth's life and from the youths themselves at age 15, and included information on the mother's relationship with her partner, maternal psychopathology, as well as youth-reported abuse. Results indicated that youths with both greater exposure to adversity in childhood and a history of an anxiety disorder displayed increased depressive severity following low levels of episodic stress compared to youths with only one or neither of these risk factors. The results are speculated to reflect the possibility that early anxiety disorders associated with exposure to adversity in childhood may be a marker of dysregulated stress responses, and may help to account for the comorbidity of depression and anxiety in some individuals.     

A single case-study of diagonistic dyspraxia

Diagonistic dyspraxia is a clinical syndrome usually characterized by involuntary and conflicting behaviors between the hands following corpus callosum lesions. In the present study, we report the case of a patient who presents such symptoms, along with a series of complex abnormal behaviors, such as carrying out an action and subsequently doing the exact opposite, or being unable to choose between two alternative decisions. The data reported in this study indicate that, at least in some patients, diagonistic dyspraxia can be associated with abnormal, antagonistic, behaviors not limited to the hands. In our view, diagonistic dyspraxia result from lesion of the posterior corpus callosum while associated complex abnormal behaviors result from concomitant anterior lesions.