The contribution of external and internal features to the matching of unfamiliar faces

The relative efficacy of external and internal features in matching unfamiliar faces was studied in three experiments in which the subjects matched target and test faces differing in terms of external or internal features, or both. In Experiment 1 only full congruency between target and test faces was considered a match; in Experiments 2 and 3 faces sharing the same external and internal features were also considered to be matches. A total of 100 subjects matched 192 pairs of target and test faces in a same-different task. Reaction times and matching errors were recorded for analyses of variance. In all three experiments performance was best when either all features matched or all features mismatched, with mismatches having a slight edge. When matches of external and internal features with the target faces were inconsistent with each other, mismatches of external features led to faster responses in Experiments 1 and 2, and mismatches of internal features led to faster responses in Experiment 3. The results suggest that since faces are configurational stimuli, face matching is influenced by the non-relevant set of features; and that mismatches, especially of external features, influence face matching more than matches do.     

Organization of behavior in unfamiliar female rabbits

Under natural conditions, female European rabbits usually spend the whole of their life in their natal groups, establishing a network of stable relationships with their group-mates, particularly with other females. Indeed, female social interactions with groupmates are ultimately responsible for the dimension, structure, and cohesion of the group itself. Despite their importance in social organization, non-reproductive female behaviors are poorly known. This study aims to provide information on the nature and distribution of these behaviors in familiar and unfamiliar milieux. For this purpose, female rabbits unfamiliar with each other were experimentally grouped, housed in outdoor enclosures new to them, and observed as they gradually familiarized with their environment and group-mates. When females were unfamiliar with both environment and group-mates, they would often mark objects (but never conspecifics) and engage in agonistic activities, preceded by approach and olfactory investigation. Once females had become familiar with their environment and group-mates, they spent a lot of time eating and self-grooming. Marking frequency decreased, and agonistic behavior became rare and appeared no longer related to introductory behaviors, which under these conditions led to amiable interactions, such as lying side by side with group-mates or grooming them. Under both unfamiliar and familiar conditions, high-ranking females appeared more active and interactive than low-ranking ones.     

The time course of processing external and internal features of unfamiliar faces

The time course of processing internal and external facial features was studied in a sequential face matching task, where first a target face was presented, followed by a test face. The exposure duration of the test face was varied systematically (90, 120, 150 ms, and self-paced). In three tasks, participants were instructed to match either the whole face, only external features, or only internal features of the target and test face. Taken together, the results in all the three tasks provide evidence for very fast matching processes. For upright faces, maximal performance was achieved at 90 ms exposure duration and longer exposure durations (120, 150 ms, self-paced) did not improve accuracy. For inverted whole faces, reduced exposure duration resulted in an increase of matching errors, suggesting that below 150 ms of exposure duration, inverted faces cannot be matched reliably. When matching selected facial features only, no such inversion effect was found. Our data challenges previous claims that external features are matched faster than internal: no difference of time course was found between external and internal features. However, external features were matched more accurately.     

Sensitivity to feature displacement in familiar and unfamiliar faces: beyond the internal/external feature distinction

Previous studies of face recognition and of face matching have shown a general improvement for the processing of internal features as a face becomes more familiar to the participant. In this study, we used a psychophysical two-alternative forced-choice paradigm to investigate thresholds for the detection of a displacement of the eyes, nose, mouth, or ears for familiar and unfamiliar faces. No clear division between internal and external features was observed. Rather, for familiar (compared to unfamiliar) faces participants were more sensitive to displacements of internal features such as the eyes or the nose; yet, for our third internal feature-the mouth no such difference was observed. Despite large displacements, many subjects were unable to perform above chance when stimuli involved shifts in the position of the ears. These results are consistent with the proposal that familiarity effects may be mediated by the construction of a robust representation of a face, although the involvement of attention in the encoding of face stimuli cannot be ruled out. Furthermore, these effects are mediated by information from a spatial configuration of features, rather than by purely feature-based information.     

Reactions to "anxiety and motor behavior"

Martens has presented and excellent and provocative paper in an extremely interesting area. He has certainly outlined most of the complexities of anxiety, discussed the limitations and strengths of various theoretical approaches to its study, and has presented alternatives to existing methods. My approach has been to try to summarize what I have held to be the major problem ares or limiting factors in the study of state anxiety (stress) and motor performance and then incorporate these problem areas into the context of Marten's conclusions.     

Decreased load on general motor preparation and visual-working memory while preparing familiar as compared to unfamiliar movement sequences

Learning movement sequences is thought to develop from an initial controlled attentive phase to a more automatic inattentive phase. Furthermore, execution of sequences becomes faster with practice, which may result from changes at a general motor processing level rather than at an effector specific motor processing level. In the current study, we examined whether these changes are already present during preparation. Fixed series of six keypresses, either familiar or unfamiliar, had to be prepared and executed/withheld after a go/nogo signal. Reaction time results confirmed that familiar sequences were executed faster than unfamiliar sequences. Results derived from the electroencephalogram showed a decreased demand on general motor preparation and visual-working memory before familiar sequences as compared to unfamiliar sequences. We propose that with familiar sequences the presetting segments of responses is less demanding than with unfamiliar sequences, as familiar sequences can be regarded as less complex than unfamiliar sequences. Finally, the decreasing demand on visual-working memory before familiar sequences suggests that sequence learning indeed develops from an attentive to an automatic phase.     

Influence of attentional focus on skilled motor performance: Performance decrement under unfamiliar focus conditions

Recent studies have demonstrated that the direction of attentional focus exerts a substantial influence on motor performance. We argue that in well-learned skills, this variable might be confounded with athletes’ familiarity with focus conditions. We studied the effect of familiarity and the direction of attentional focus on performance in two experiments using 2 (familiarity) × 2 (direction) within-subject designs. A significant main effect of familiarity—that is, better performance under familiar compared with unfamiliar focus conditions—confirmed the influence of familiarity on motor performance. Results are consistent with existing concepts, but lead to different consequences when applied to sport and exercise.     

Psychophysiological assessment during exposure in driving phobic patients

A comprehensive assessment of fear or anxiety requires measurement of both self-report and physiological responses. Respiratory abnormalities have been rarely examined during real-life exposure, although they are an integral part of fear. Twenty-one women with a specific driving phobia and 17 nonphobic women were psychophysiologically monitored during 2 highway-driving sessions; phobic women completed an additional session. Respiratory movements, end-tidal partial pressure of carbon dioxide, an electrocardiogram, skin conductance, and skin temperature were recorded. Phobic patients differed from control participants both physiologically and experientially before, during, and after exposure. Effect size during exposure was large for the authors' measure of hyperventilation. Discriminant analysis indicated that multiple physiological measures contributed nonredundant information and correctly classified 95% of phobic and control participants. Thus, selected respiratory and autonomic measures are valid diagnostic and therapeutic outcome criteria for this situational phobia.     

The effects of safety behavior availability versus utilization on inhibitory learning during exposure

ABSTRACT

This study re-analyzes data from Sy and colleagues (2011; Behaviour Research and Therapy, 49, 305–314) comparing safety behavior availability (SBA) to safety behavior utilization (SBU) during exposure therapy for claustrophobic concerns. The present investigation assessed differential rates of inhibitory learning (i.e. change in danger expectancy and coping self-efficacy) between SBA and SBU before, during, and after a single-session treatment. Thirty-nine participants with marked claustrophobic fear completed six consecutive 5-minute exposure trials in a claustrophobia chamber. Participants in the SBA condition exhibited more interference with inhibitory learning relative to the SBU condition. Danger expectancy was significantly higher in the SBA group and decreased at a markedly slower rate across exposure trials relative to SBU. Coping self-efficacy was also significantly lower among participants in the SBA condition, although groups demonstrated similar rates of change across trials. Limitations, clinical implications, and future directions are discussed.     

Infants’ expressive behaviors to mothers and unfamiliar partners during face-to-face interactions from 4 to 10 months

Changes in the organization of infant looking, facial expressions, and vocalizations were examined over age (4, 7, and 10 months) and with different social partners. Although infants at all ages accompanied smiling with looking at both mothers and unfamiliar partners, 7- and 10-month infants accompanied vocalization with looking only when they were with mothers. Seven- and 10-month-olds vocalized with unfamiliar partners only when they were smiling at the same time. When mothers stopped talking, infants reduced smiling significantly at all ages, yet vocalized more at 10 months. In the second half of the first year, there are fundamental changes in the coordination of infant expressive behaviors that reveal a keen attunement to variations in maternal behavior and the familiarity of social partners.     

Variability of determinism in motor behavior

In investigations into perception-action systems, variability of observable behavior may be considered to (a) interfere with inquiry, (b) be neither detrimental nor particularly useful to inquiry, or (c) play a crucial role in inquiry. The authors underscore recent suggestions that alternative (c) is a preferred strategy for the study of many motor behaviors. In tutorial fashion, the authors review the concepts of variability and determinism with respect to postural and rhythmic movements. Study of the variability of those behaviors has revealed crucial features suggestive of underlying mechanisms and control, such as particular blends of noise and determinism (piecewise determinism). It has also revealed general lessons (for example, more variable does not mean more random and more controllable does not mean more deterministic) that may extend to other classes of perceptual behavior.     

Effects of dividing attention during encoding on perceptual priming of unfamiliar visual objects

According to the distractor-selection hypothesis (Mulligan, 2003), dividing attention during encoding reduces perceptual priming when responses to non-critical (i.e., distractor) stimuli are selected frequently and simultaneously with critical stimulus encoding. Because direct support for this hypothesis comes exclusively from studies using familiar word stimuli, the present study tested whether the predictions of the distractor-selection hypothesis extend to perceptual priming of unfamiliar visual objects using the possible/impossible object decision test. Consistent with the distractor-selection hypothesis, Experiments 1 and 2 found no reduction in priming when the non-critical stimuli were presented infrequently and non-synchronously with the critical target stimuli, even though explicit recognition memory was reduced. In Experiment 3, non-critical stimuli were presented frequently and simultaneously during encoding of critical stimuli; however, no decrement in priming was detected, even when encoding time was reduced. These results suggest that priming in the possible/impossible object decision test is relatively immune to reductions in central attention and that not all aspects of the distractor-selection hypothesis generalise to priming of unfamiliar visual objects. Implications for theoretical models of object decision priming are discussed.     

Development of hand-eye dominance in relation to verbal self-regulation of motor behavior

The development of the relation between hand-eye dominance and verbal self-control of motor behavior was examined with 4- and 5-year-olds. Performances of subjects falling into either crossed or consistent hand-eye dominance categories were compared on a two-choice button-pushing task. Children performed this with their dominant hand in one of two conditions: verbalizing and not verbalizing their button-pushing activity. Results showed that crossed hand-eye dominant children gave significantly poorer performances than consistent hand-eye dominant children and that the former used their self-instructions in a motoric manner. These findings were interpreted as supporting the view that the functions of cerebral hemispheres in children with crossed dominance are more immature than those in children with consistent dominance.     

Driving tests with older patients: effect of unfamiliar versus familiar vehicle

The aim of the study was to study the effect, for older license holders, of taking a driving test with an unfamiliar vehicle, as compared to their own cars. The study population consisted of licensed patients 65–85 years referred to the Traffic Medicine Centre (TrMC), Huddinge University Hospital, for an evaluation of their medical and cognitive fitness to drive. In the clinical practice of TrMC, driving tests have been used since 1997, with inspectors from the Swedish National Road Administration (SNRA) acting as evaluators. Initially, patients were allowed to use their own cars. From the beginning of the year 2000, however, dual brakes were made mandatory and most evaluations were then made with SNRA cars. When comparing the outcomes of driving tests from the period prior to 2000 (n=96) and after 2000 (n=69), it was found that the number of drivers who failed the test increased by 16%. Also, those who passed the test after more than one trial decreased by 20%. The potential of the neuropsychological assessment to correctly classify drivers in outcome groups was considerably reduced in the period after 2000. These results support the view that, for older drivers with cognitive deterioration, the need to adapt to an unfamiliar vehicle represents a supplementary cognitive load that may compromise their driving ability and the validity of the assessment. A measure aimed only at increasing the safety of examiners and examinees thus had an unintended side-effect that is detrimental to older clinical populations.     

Development of oral motor behavior related to the skill assisted spoon feeding

Milestones in the typical development of eating skills are considered to be nippling (breast or bottle), eating from a spoon, drinking from a cup, biting and chewing.The purpose of this research was to study the development and consolidation of oral motor behavior related to the skill assisted spoon feeding in young infants. The present study longitudinally investigated the development of this skill in 39 healthy children from the start of spoon feeding until the skill was acquired. The Observation List Spoon Feeding with 7 observation items for oral motor behavior and 6 items for abnormal behavior was used. Results showed that infants between 4 and 8 months of age needed 5.7 weeks (SD 2.1), with a range of 8 weeks (from 2 to 10 weeks) to acquire this skill. No significant correlation (p = .109) between age at start spoon feeding and weeks needed to develop the skill was found. During this period oral motor behavior consolidated and abnormal behavior diminished.With this study it is shown that the period in weeks needed to acquire the oral motor behavior for the skill assisted spoon feeding is important in case of feeding problems.     

Infants' attribution of a goal to a morphologically unfamiliar agent

How do infants identify the psychological actors in their environments? Three groups of 12‐month‐old infants were tested for their willingness to encode a simple approach behavior as goal‐directed as a function of whether it was performed by (1) a human hand, (2) a morphologically unfamiliar green object that interacted with a confederate and behaved intentionally, or (3) the same unfamiliar green object that behaved in a matched, but apparently random manner. Using a visual habituation technique, only infants in the first two conditions were found to encode the approach behavior as goal‐directed. Thus infants appear able to attribute goals to non‐human, even unfamiliar agents. These results imply that by the end of the first year of life infants have a broad notion of what counts as an agent that cannot easily be reduced to humans, objects that are perceptually similar to humans, or objects that display self‐propulsion.