Can wild common marmosets (Callithrix jacchus) solve the parallel strings task?

Patterned string tasks are a test of perceptual capacity and the understanding of means-end connections. Primates can solve complex forms of this task in laboratories. However, this may not indicate the level of such cognition that is commonly employed in the wild, where decision-making time is often short and distractions such as predator avoidance and competition between conspecifics are often prevalent. The current study tests whether wild common marmosets (Callithrix jacchus) can successfully complete the simplest form of the patterned string task, parallel strings, while in their natural environment. Although 12 out of 13 marmosets could successfully complete the task, in previous laboratory-based studies on primates, the errors at this task by all primate species tested were consistently lower than in the present study. This is probably explained by the added difficulties imposed by the natural setting of the task in the present study, exemplified by a significant increase in observed vigilance behaviour by subject animals prior to attempts at the task that were unsuccessful. The undertaking of such tasks by common marmosets in situ probably provides a more reasonable representation of the levels of cognitive capacity expressed by this species in the wild than do laboratory-based studies of the task.     

Newborns' recognition of changing and unchanging aspects of schematic faces

The present study investigated newborns' ability to discriminate, recognize, and learn visual information embedded in the schematic face-like patterns preferred at birth. Four experiments were carried out using the visual-paired comparison paradigm. Results indicated that newborns discriminated face-like stimuli relying on their internal features (Experiments 1 and 4) and recognized a perceptual invariance between face-like configurations in conditions of low (Experiment 2) and high-perceptual variability (Experiment 3) of their inner elements. Altogether, data show that the presence of the preferred structure that schematically defines a face, displaying a triplet of elements in the correct locations for eyes and mouth, does not constitute a limit that constrains newborns' face learning processes.     

Relationships between perceptual defence reactions and subjective tendencies in the phenomenal representation of facial displays of affect

The present study examines if non-veridical reports of a stimulus-motif presented below the threshold for correct recognition are related to subjective tendencies in the ordinary perception of thermatically related stimuli. Sixty-four subjects were tested with the standard picture of Kragh's Defence Mechanism Test (DMT) which reflects a theme of aggression and threat. Stimulus-inadequate report of the picture-motif were related to the subject's phenomenal representation of video-recorded facial displays of anger, fear, sadness, and joy. The results demonstrate a correspondence between the individual's perceptual distortions, eliminations, or additions to the threatening subliminal stimulus and his or her phenomenal representation of the supraliminal affective stimuli.     

Personality development in old age relates to physical health and cognitive performance: Evidence from the Berlin Aging Study II

We examine how late-life personality development relates to overall morbidity as well as specific performance-based indicators of physical and cognitive functioning in 1,232 older adults in the Berlin Aging Study II (aged 65–88 years). Latent growth models indicated that, on average, neuroticism and conscientiousness decline over time, whereas extraversion and openness increase and agreeableness remains stable. Higher morbidity and worse grip strength were associated with higher neuroticism. Lower grip strength was further associated with lower openness, attenuated increases in extraversion, decreases in agreeableness and accelerated declines in conscientiousness. Moreover, those with poor perceptual speed reported higher neuroticism and lower conscientiousness. We also found age- and gender-differential associations between physical health and cognitive performance with levels of and changes in personality.     

Influence of cue word perceptual information on metamemory accuracy in judgement of learning

Previous studies have suggested that perceptual information regarding to-be-remembered words in the study phase affects the accuracy of judgement of learning (JOL). However, few have investigated whether the perceptual information in the JOL phase influences JOL accuracy. This study examined the influence of cue word perceptual information in the JOL phase on immediate and delayed JOL accuracy through changes in cue word font size. In Experiment 1, large-cue word pairs had significantly higher mean JOL magnitude than small-cue word pairs in immediate JOLs and higher relative accuracy than small-cue pairs in delayed JOLs, but font size had no influence on recall performance. Experiment 2 increased the JOL time, and mean JOL magnitude did not reliably differ for large-cue compared with small-cue pairs in immediate JOLs. However, the influence on relative accuracy still existed in delayed JOLs. Experiment 3 increased the familiarity of small-cue words in the delayed JOL phase by adding a lexical decision task. The results indicated that cue word font size no longer affected relative accuracy in delayed JOLs. The three experiments in our study indicated that the perceptual information regarding cue words in the JOL phase affects immediate and delayed JOLs in different ways.     

On-court position and handedness in visual anticipation of stroke direction in tennis

ObjectivesIn racket sports, players integrate information picked up from their opponent's kinematics and contextual cues like on-court position into shot outcome anticipation. In view of suggested difficulties with anticipating left-handed opponents' action intentions, here we examined whether an opponent's handedness interacts with position-dependency in visual anticipation.Design and methodFollowing a 2 (Group) x 2 (Handedness) x 2 (Position) x 3 (Temporal Occlusion) factorial design, 20 tennis players and 20 non-players predicted directional outcome of temporally manipulated point-light animations of identical left- and right-handed forehand groundstrokes performed near vs. far from the court's midline.ResultsTennis players' response selection was mostly affected by an opponent's on-court position, particularly at an early stage of a hitting movement. Opponents' handedness affected response selection similarly in both groups (i.e., bias towards down-the-line predictions against left-handed strokes occluded at racket-ball-contact), but it did not interact with on-court position.ConclusionsFindings highlight that on-court position, and opponents' handedness to some extent as well, appears relevant for skilled visual anticipation in tennis.     

Instruction-driven processing in human perceptual learning

We conducted a series of experiments to determine the relative contribution of unsupervised versus controlled mechanisms to the intermixed-blocked effect. In Experiment 1, participants received pre-exposure instructions prompting a search for differences between stimuli, in keeping with past studies, and the intermixed-blocked effect was observed. In the remaining experiments, participants did not receive the aforementioned instructions, but instead were instructed either to simply observe the stimuli (Experiment 2) or in relation to a masking task (Experiment 3). None of the latter experiments produced an intermixed-blocked effect, suggesting that the effect found in Experiment 1 was driven by the instructions to search for differences, consistent with a controlled processing account of the effect. Moreover, we tested a prediction assuming the operation of a search strategy against one assuming the operation of a short-term habituation mechanism and found evidence more consistent with the search strategy hypothesis. We formulate a new account of the intermixed-blocked effect in humans based on an instruction-driven search and discuss how the account could explain many findings in the human literature.     

The sound of motion in spoken language: visual information conveyed by acoustic properties of speech

Language is generally viewed as conveying information through symbols whose form is arbitrarily related to their meaning. This arbitrary relation is often assumed to also characterize the mental representations underlying language comprehension. We explore the idea that visuo-spatial information can be analogically conveyed through acoustic properties of speech and that such information is integrated into an analog perceptual representation as a natural part of comprehension. Listeners heard sentences describing objects, spoken at varying speaking rates. After each sentence, participants saw a picture of an object and judged whether it had been mentioned in the sentence. Participants were faster to recognize the object when motion implied by speaking rate matched the motion implied by the picture. Results suggest that visuo-spatial referential information can be analogically conveyed and represented.     

Visual laterality responses to different emotive stimuli by red-capped mangabeys, Cercocebus torquatus torquatus

Hemispheric asymmetry in emotional perception has been put forward by different theories as the right hemisphere theory or the valence theory. But no consensus was found about the role played by both hemispheres. So, in order to test the different theories, we investigated preferential use of one eye in red-capped mangabeys, at the individual as well as at the group level. In this study we investigated the influence of the emotional value of stimuli on the direction and strength of visual preference of 14 red-capped mangabeys. Temporal stability of the bias of use of a given eye was evaluated by comparing our current results to those obtained 2.5 months previously. Two experimental devices, a tube and a box, tested five different stimuli: four food types varying in palatability and a neutral stimulus. The subjects’ food preferences were evaluated before testing the laterality. The mangabeys used their left eyes predominantly at the group level for the tube task. The majority of the subjects showed a visual preference at the individual level for the box task, but this bias was not present at the group level. As the palatability of the stimuli increased, the number of lateralized subjects and the number of subjects using preferentially their left eye increased. Similarly, the strength of laterality was related to food preference. Strength of laterality was significantly higher for subjects using their left eye than for subjects using their right eye. Preferential use of a given eye was stable over short periods 2.5 months later. Our data agree with reports on visual laterality for other species. Our results support the valence theory of a hemispheric sharing of control of emotions in relation to their emotional value.