Mental time travel into the past and the future in healthy aged adults: an fMRI study

Remembering the past and envisioning the future rely on episodic memory which enables mental time travel. Studies in young adults indicate that past and future thinking share common cognitive and neural underpinnings. No imaging data is yet available in healthy aged subjects. Using fMRI, we scanned older subjects while they remembered personal events (PP: last 12 months) or envisioned future plans (FP: next 12 months). Behaviorally, both time-periods were comparable in terms of visual search strategy, emotion, frequency of rehearsal and recency of the last evocation. However, PP were more episodic, engaged a higher state of autonoetic consciousness and mental visual images were clearer and more numerous than FP. Neuroimaging results revealed a common network of activation (posterior cingulate cortex, precuneus, prefrontal cortex, hippocampus) reflecting the use of similar cognitive processes. Furthermore, the episodic nature of PP depended on hippocampal and visuo-spatial activations (occipital and angular gyri), while, for FP, it depended on the inferior frontal and lateral temporal gyri, involved in semantic memory retrieval. The common neural network and behavior suggests that healthy aged subjects thought about their future prospects in the past. The contribution of retrospective thinking into the future that engages the same network as the one recruited when remembering the past is discussed. Within this network, differential recruitment of specific areas highlights the episodic distinction between past and future mental time travel.     

Contributions of contingencies in modern societies to "privacy" in the behavioral relations of cognition and emotion

The aim of this paper is to examine specific features of modern individualistic societies that contribute to "emotions" and "cognitions" becoming a matter of privacy. Although some behavior analysts identify emotions and cognitions as "private events," we argue with Skinner (1945) that cognitions and emotions are relations among events and that their origin is in public events in the contingencies of reinforcement maintained by other people. Guided by Elias (1939/1996), we suggest that the shift from feudal economies to market economies involved the increasing individualization of society's members. This individualizing process includes the socially maintained contingencies that bring some verbal responses under control of private stimulation and reduce the magnitude of some verbal responses to a covert level. Behavioral relations in which either stimuli or responses (or both) cannot be observed by others set the stage for a concept of "privacy." Changes in societal contingencies that gave rise to individualization and the attribution of privacy to cognitions and emotions are suggested to include the following: (a) increasing frequency of individual consequences that have no apparent or direct relevance to the group; (b) increasing numbers of concurrent contingencies and choice requirements; (c) conflicts between immediate and delayed consequences for the individual; and (d) conflicts between consequences for the individual and for the group.     

Imitation and repetition of prosodic contour in vocal interaction at 3 months

This study investigates vocal imitation of prosodic contour in ongoing spontaneous interaction with 10- to 13-week-old infants. Audio recordings from naturalistic interactions between 20 mothers and infants were analyzed using a vocalization coding system that extracted the pitch and duration of individual vocalizations. Using these data, the authors categorized a sample of 1,359 vocalizations on the basis of 7 predetermined contours. Pairs of identical successive vocalizations were considered to be imitations if they involved both partners or repetitions if they were produced by the same partner. Results show that not only do mothers and infants imitate and repeat prosodic contour types in the course of vocal interaction but they do so selectively. Indeed, different contours are imitated and repeated by each partner. These findings suggest that imitation and repetition of prosodic contours have specific functions for communication and vocal development in the 3rd month of life.     

What matters in the associative learning of visual cues in foraging parasitoid wasps: colour or brightness?

Visual cues are known to be used by numerous animal taxa to gather information on quality and localisation of resources. Because environmental lighting can interfere with the spectral features of visual cues, the specific characteristics of the colour signals that promote forager decision and learning are still not known in the majority of insects (excepted in bees). We analysed the effect of previous experience on the use of visual information by the wasp Venturia canescens, a parasitoid of pyralidae, in the context of host searching. These parasitoids search for hosts concealed in several fruit species, so visual cues from the host microhabitat could play a key role in host finding. We also investigated the type of visual cues on which wasps based their decision. We tested whether wasps are able to associate an achromatic cue (brightness) or a chromatic one (hue, i.e. dominant wavelength and/or chroma) with the presence of hosts. Our results show that in the context of host foraging, chromatic cues are more reliable than brightness in achieving the associative learning process. Therefore, understanding the behavioural ecology of foraging should make use of the knowledge about the visual information used.     

Limits on bilingualism revisited: Stress ‘deafness’ in simultaneous French–Spanish bilinguals

We probed simultaneous French–Spanish bilinguals for the perception of Spanish lexical stress using three tasks, two short-term memory encoding tasks and a speeded lexical decision. In all three tasks, the performance of the group of simultaneous bilinguals was intermediate between that of native speakers of Spanish on the one hand and French late learners of Spanish on the other hand. Using a composite stress ‘deafness’ index measure computed over the results of the three tasks, we found that the performance of the simultaneous bilinguals is best fitted by a bimodal distribution that corresponds to a mixture of the performance distributions of the two control groups. Correlation analyses showed that the variables explaining language dominance are linked to early language exposure. These findings are discussed in light of theories of language processing in bilinguals.     

Musical structure modulates semantic priming in vocal music

It has been shown that harmonic structure may influence the processing of phonemes whatever the extent of participants' musical expertise [Bigand, E., Tillmann, B., Poulin, B., D'Adamo, D. A., & Madurell, F. (2001). The effect of harmonic context on phoneme monitoring in vocal music. Cognition, 81, B11-B20]. The present study goes a step further by investigating how musical harmony may potentially interfere with the processing of words in vocal music. Eight-chord sung sentences were presented, their last word being either semantically related (La girafe a un tres grand cou, The giraffe has a very long neck) or unrelated to the previous linguistic context (La girafe a un tres grand pied, The giraffe has a very long foot). The target word was sung on a chord that acted either as a referential tonic chord or as a congruent but less referential subdominant chord. Participants performed a lexical decision task on the target word. A significant interaction was observed between semantic and harmonic relatedness suggesting that music modulates semantic priming in vocal music. Following Jones' dynamic attention theory, we argue that music can modulate semantic priming in vocal music, by modifying the allocation of attentional resource necessary for linguistic computation.     

The rules versus similarity distinction

The distinction between rules and similarity is central to our understanding of much of cognitive psychology. Two aspects of existing research have motivated the present work. First, in different cognitive psychology areas we typically see different conceptions of rules and similarity; for example, rules in language appear to be of a different kind compared to rules in categorization. Second, rules processes are typically modeled as separate from similarity ones; for example, in a learning experiment, rules and similarity influences would be described on the basis of separate models. In the present article, I assume that the rules versus similarity distinction can be understood in the same way in learning, reasoning, categorization, and language, and that a unified model for rules and similarity is appropriate. A rules process is considered to be a similarity one where only a single or a small subset of an object's properties are involved. Hence, rules and overall similarity operations are extremes in a single continuum of similarity operations. It is argued that this viewpoint allows adequate coverage of theory and empirical findings in learning, reasoning, categorization, and language, and also a reassessment of the objectives in research on rules versus similarity.     

The role of context in remembering familar persons: insights from semantic dementia

Semantic dementia (SD) is a progressive condition characterized by an insidious and gradual breakdown in semantic knowledge. Patients suffering from this condition gradually lose their knowledge of objects and their attributes, concepts, famous persons, and public events. In contrast, these patients maintain a striking preservation of autobiographical memory. The aim of the present study was to examine in a patient suffering from SD the role of context in the ability to recall knowledge of familiar persons. In an experiment, patient J.M. was asked to name and identify familiar persons that appeared on family photographs from recent and remote periods of her life. In the first experimental condition, the pictures represented personally familiar persons present in a specific spatial and temporal context. In a second experimental condition, the pictures showed personally familiar persons who were presented without any specific episodic context. Results indicate that the patient was able to name and identify familiar persons irrespective of the context of presentation (with/without context) and of the time period (recent/remote). No temporal gradient was found using family photographs. Finally, in contrast with familiar persons, J.M. presented a severe anomia for celebrities. Results are discussed in light of recent research in the field.     

Cognitive function and depression in symptom resolution in schizophrenia patients treated with an atypical antipsychotic

OBJECTIVE: To investigate which cognitive and affective features contribute most to responder/non-responder group separation during a switching trial with atypical antipsychotic. DESIGN: A prospective open trial with an atypical antipsychotic (olanzapine). PATIENTS: One hundred and thirty-four patients meeting diagnostic criteria for schizophrenia, schizophreniform or schizoaffective disorder began an 8-week open-label olanzapine treatment at a dose of 5 mg/day which was increased to 10 mg/day after one week. INTERVENTIONS: Olanzapine during 8 weeks. Patients were considered as responders if their BPRS score decreased of at least 20% (n = 96) and non-responders if it did not (n = 38). Neuropsychological assessments were carried out at baseline, at four and at eight weeks. RESULTS: Neurocognitive measures were analyzed for discriminate factors between responder and non-responder groups. A regression analysis was applied to explain the effects of depression on each cognitive variable. Depression was found to be a weak discriminant factor, however this finding could not firmly establish that depression is a potential factor in explaining deficits and improvements in cognition.