Finger inter-dependence: linking the kinetic and kinematic variables

We studied the dependence between voluntary motion of a finger and pressing forces produced by the tips of other fingers of the hand. Participants moved one of the fingers (task finger) of the right hand trying to follow a cyclic, ramp-like flexion-extension template at different frequencies. The other fingers (slave fingers) were restricted from moving; their flexion forces were recorded and analyzed. Index finger motion caused the smallest force production by the slave fingers. Larger forces were produced by the neighbors of the task finger; these forces showed strong modulation over the range of motion of the task finger. The enslaved forces were higher during the flexion phase of the movement cycle as compared to the extension phase. The index of enslaving expressed in N/rad was higher when the task finger moved through the more flexed postures. The dependence of enslaving on both range and direction of task finger motion poses problems for methods of analysis of finger coordination based on an assumption of universal matrices of finger interdependence.     

Effects of auditory input in individuation tasks

Under many conditions auditory input interferes with visual processing, especially early in development. These interference effects are often more pronounced when the auditory input is unfamiliar than when the auditory input is familiar (e.g. human speech, pre‐familiarized sounds, etc.). The current study extends this research by examining how auditory input affects 8‐ and 14‐month‐olds’ performance on individuation tasks. The results of the current study indicate that both unfamiliar sounds and words interfered with infants’ performance on an individuation task, with cross‐modal interference effects being numerically stronger for unfamiliar sounds. The effects of auditory input on a variety of lexical tasks are discussed.     

When we feel good and bad about ourselves: self-esteem memories across cultures

Young adults in the United States, Croatia, and China described personal episodes of times when they felt especially good or bad about themselves. These self-esteem memories were either recent (episodes that occurred during the previous 4 weeks) or remote (episodes that occurred between the ages of 10 and 15). Systematic content differences between memories of positive and negative self-worth were apparent primarily for remote rather than for recent memories. Across cultures, long-lasting positive memories frequently represented achievement themes, whereas negative memories frequently represented social themes. Links between achievement success and positive self-regard, and between social distress and negative self-regard, are explained using theories of self-esteem and autobiographical memory.     

Physical health and social network characteristics as determinants of mental health across cultures

This study examines cross-cultural differences in the etiology of depression and anxiety, two common indicators of mental health problems. Using an ethnically diverse sample of 162 college students, we found that chronic physical symptoms and social network characteristics, particularly network quality, were predictive of both depression and anxiety, yet their effects were mediated by ethnicity. Multiple regression analyses showed that social network quality, compared to physical health, was a much stronger predictor of mental health in Caucasian students, whereas among students of Asian/Pacific descent, physical health was a much stronger predictor of mental health than the social network characteristics. The observed differences were particularly strong for anxiety, which was not significantly associated with physical health in Caucasian students or social network size and quality in the Asian/Pacific group. Theoretical and clinical implications of the results are discussed.     

Physical health and social network characteristics as determinants of mental health across cultures

This study examines cross-cultural differences in the etiology of depression and anxiety, two common indicators of mental health problems. Using an ethnically diverse sample of 162 college students, we found that chronic physical symptoms and social network characteristics, particularly network quality, were predictive of both depression and anxiety, yet their effects were mediated by ethnicity. Multiple regression analyses showed that social network quality, compared to physical health, was a much stronger predictor of mental health in Caucasian students, whereas among students of Asian/Pacific descent, physical health was a much stronger predictor of mental health than the social network characteristics. The observed differences were particularly strong for anxiety, which was not significantly associated with physical health in Caucasian students or social network size and quality in the Asian/Pacific group. Theoretical and clinical implications of the results are discussed.     

Effects of joint immobilization on standing balance

We investigated the effect of joint immobilization on the postural sway during quiet standing. We hypothesized that the center of pressure (COP), rambling, and trembling trajectories would be affected by joint immobilization. Ten young adults stood on a force plate during 60 s without and with immobilized joints (only knees constrained, CK; knees and hips, CH; and knees, hips, and trunk, CT), with their eyes open (OE) or closed (CE). The root mean square deviation (RMS, the standard deviation from the mean) and mean speed of COP, rambling, and trembling trajectories in the anterior–posterior and medial–lateral directions were analyzed. Similar effects of vision were observed for both directions: larger amplitudes for all variables were observed in the CE condition. In the anterior–posterior direction, postural sway increased only when the knees, hips, and trunk were immobilized. For the medial–lateral direction, the RMS and the mean speed of the COP, rambling, and trembling displacements decreased after immobilization of knees and hips and knees, hips, and trunk. These findings indicate that the single inverted pendulum model is unable to completely explain the processes involved in the control of the quiet upright stance in the anterior–posterior and medial–lateral directions.     

Gesture and metaphor comprehension: Electrophysiological evidence of cross-modal coordination by audiovisual stimulation

In recent years, studies have suggested that gestures influence comprehension of linguistic expressions, for example, eliciting an N400 component in response to a speech/gesture mismatch. In this paper, we investigate the role of gestural information in the understanding of metaphors. Event related potentials (ERPs) were recorded while participants viewed video clips of an actor uttering metaphorical expressions and producing bodily gestures that were congruent or incongruent with the metaphorical meaning of such expressions. This modality of stimuli presentation allows a more ecological approach to meaning integration. When ERPs were calculated using gesture stroke as time-lock event, gesture incongruity with metaphorical expression modulated the amplitude of the N400 and of the late positive complex (LPC). This suggests that gestural and speech information are combined online to make sense of the interlocutor’s linguistic production in an early stage of metaphor comprehension. Our data favor the idea that meaning construction is globally integrative and highly context-sensitive.     

Ethological analysis of neuropeptides and psychotropic drugs: Effects on intraspecies aggression and sociability of isolated mice

The experiments on mice (under the condition of agonistic interactions) have shown increases and decreases in certain forms of species-specific behavior (aggression, defense, sociability) when synthetic peptides and psychotropic drugs were administered. MIF-1, TRH, and LH-RH (acute injections) enhance aggression in isolated mice while somatostatin reduces it. MIF–1 antagonizes the antiaggressive effects of haloperidol, muscimol, and morphine. ACTH 1–24 counteracts the action of diaze-pam on attacks and threats. Somatostatin reduces both aggression and sociability and that effect may be potentiated by diazepam. Neo-endorphin injected together with diazepam reduces aggression and enhances sociability. A combination of synthetic neuropeptides and well known psychotropic drugs (neuroleptics, tranquil-izers, and others) may be more effective for the control of aggression and sociability than the psychotropic drugs employed alone.