Characterization of state transitions in spatially distributed,chaotic, nonlinear,dynamical systems in cerebral cortex

The neurons of cerebral cortex are largely autonomous and generate activity that is manifested in trains of microscopic axonal action potentials. The neurons interact by sparse but numerous synaptic connections to generate macroscopic dendritic activity patterns that are observed in electroencephalographic (EEG) waves. The macroscopic patterns are constructed by the populations and they shape the output of cortical neurons in parallel arrays. Sensory cortexes receive sensory information in the form of microscopic action potentials, which induce state transitions in population dynamics. Each state transition transforms sensory information to perceptual meaning. The EEG reflects both kinds of activity. The sensory input is accessed by time ensemble averaging, whereas the perceptual output is found by spatial ensemble averaging. Spatial phase gradients in the EEG are useful for identifying EEG segments in a sequence of state transitions in response to sensory input. The rapidity and flexibility with which they take place give strong reason to postulate that the mechanism for the construction of these sequences of patterns is a dynamical system operating in a chaotic domain.     

Sexual assault: Myths and stereotypes among Australian adolescents

Myths and stereotypes about sexual assault reflect a society which excuses perpetrators of assault and blames victims for failing to control men's sexuality. Such views are well-established by early adulthood, but there is little research with adolescents. This study surveyed two hundred forty-four 14–16 year old Australian high school students (105 male, 139 female), of Anglo-European descent. Males were significantly more likely to endorse sexual assault myths, to agree that forced sex was acceptable in some situations, and to hold false stereotypes about sexual assault. Males also held more restrictive attitudes toward women's roles and endorsed a greater level of sexism in dating relationships. This suggests that male and female adolescents have differing expectations of dating relationships, which may underlie sexual assault within relationships. Assault-supportive attitudes are apparent at a young age, supporting the need for educational and social interventions targeting young people.     

Emotional Self-Awareness,Eating Disorders,and Racial Identity Attitudes in African American Women

Certain racial identity attitudes may involve diminished internal emotional awareness, features of a syndrome known as “alexithymia,” which has been observed in survivors of extreme trauma. This study found that levels of alexithymia, but not eating disorders, were related to attitudes characteristic of early stages of racial identity development among African American women.     

A plea for more intervision

The author presents an argument for tolerance, mutual understanding and reconciliation in psychotherapy, instead of a continued emphasis of schools. Psychotherapists' work with clients is proposed as a likely area for mutual understanding, rather than continued emphasis on their particular theories and academic matters. Psychotherapeutic intervision groups in which a small number of therapists voluntarily discuss their cases with peers from various backgrounds have become increasingly common again in recent years.Slightly revised version of a presentation made at the Georgetown Family Center Symposium in November 1995.     

The curative fantasy in group psychotherapy

The concept of a curative fantasy includes patient's conscious and unconscious hopes and expectations of what is necessary for their relief of suffering. On entering group psychotherapy these elements emerge in the treatment matrix. This paper describes how patients with significant deficits in their intrapsychic organization express their curative fantasies through the development of selfobject transferences. The concept illuminates aspects of patients entering and forming a group as well as some elements in unanticipated terminations.     

Differentiation of brain damage among low IQ subjects with three projective techniques.

Using a battery of three projective techniques (Rorschach, Hand Test, Bender-Gestalt) only slight discrimination was found between low IQ subjects classified according to the presence or absence of brain trauma (exogenous vs endogenous), while substantial discrimination was obtained between the same subjects categorized in terms of "lower" (60-74) and "higher" (75-89) FS WAIS IQ. All four groups used in this study had been first equated on sex and age. Results were interpreted as supporting the position that some sort of brain impairment underlies most or all retardation. Question was raised concerning the efficacy of projective techniques for diagnosing organicity in subjects of average or better intelligence.     

Conditioned fear and startle magnitude: effects of different footshock or backshock intensities used in training

In Experiment 1 four groups of rats received 30 light-shock pairings using footshock intensities of either .2, .4, .8, or 1.6 mA. One day later all rats were tested for startle by presenting tones in the presence or absence of the light CS. Potentiated startle (the difference between startle on light-tone vs tone-alone trials) was nonmonotonically related to the shock intensity used in training, with the greatest potentiation at intermediate shock levels. Experiment 3 demonstrated a similar relationship when backshocks instead of footshocks were used. In Experiment 2 rats were trained with either a moderate or high shock and then given an extended extinction-test session 1 day later. The moderate-shock group showed a gradual decline in potentiated startle over extinction. The high-shock group showed a nonmonotonic extinction curve where potentiation progressively increased toward the middle of extinction and dissipated thereafter. The results suggest that acoustic startle bears an inverted U-shaped relationship to fear and are discussed in relation to other studies concerned with this issue.     

Age comparative factor analysis of ability variables in adulthood and old age

The generality of ability factor structure in adulthood and old age was investigated using simultaneous maximum likelihood procedures. Data were analyzed for 198 young individuals (age range of 15–32 years), 156 younger old individuals (age range of 53–68 years), and 156 older old individuals (69–91 years). Variables were nine tests marking three ability factors: Verbal Comprehension, Sensitivity to Problems and Semantic Redefinition. Results indicated no changes in the number of factors and no psychologically important shifts in salient factor loadings. Increasingly larger factor covariances, however, were obtained in the two older groups. The results supported the generalizability of ability structures to late life at the level of factor loadings. The implications of these results for the dedifferentiation hypothesis were not clear cut. The consistency of the number of factors across age groups precluded strong support for this hypothesis, The increased factor covariances could be construed as modest support for this hypothesis, but other interpretations were possible.     

The sensing of retinal motion

The apparent relative motion of physically stationary objects that frequently occurs as the head is moved in a frontoparallel plane is almost always in the direction expected from the projection into the distal world of the relative motion of the images on the eye. It is hypothesized that this is the result of the perceptual underestimation of the depth between the objects. If a perceptual overestimation of the depth were produced, it was predicted that the apparent relative motion would be in a direction opposite to that expected from the projection of the retinal motions. This prediction was tested using the binocular disparity cue to produce perceptual overestimation of the slant (depth) of a luminous line. In this case, perceived slant was the indicator of perceived depth, and perceived rotation concomitant with the motion of the head was the indicator of perceived relative motion. The results support the prediction and also provide some support for a theoretically derived equation specifying the relation between these two perceptual variables.     

Verbal and nonverbal recognition memory in aphasic and nonaphasic stroke patients

The ability to retain lists of verbal and nonverbalizable items across recurrent recognition tasks was tested in three groups: (1) stroke patients with a left-brain lesion and aphasia, (2) stroke patients with a right-brain lesion and left hemiplegia, and (3) nonneurologically impaired outpatients. As determined with signal detection measures, aphasics were deficient in discriminating words that were to be remembered from those that were not; their recognition of nonverbal visual (geometric art) or auditory (bird calls) patterns, however, was unimpaired. Left hemiplegics showed the opposite pattern. After a long-term interval (<10 min), correct recognition of words was diminished in all groups whereas recognition of visual patterns increased. Both groups of stroke patients adopted material-specific decision criteria which in part accounted for the dissociation of verbal and nonverbal recognition memory by laterality of lesion. Item analysis indicated that aphasics' verbal memory difficulties were affected by acoustic-semantic confusion of list words.