Hemispheric specialization for spatial frequency processing in the analysis of natural scenes

Experimental data coming from visual cognitive sciences suggest that visual analysis starts with a parallel extraction of different visual attributes at different scales/frequencies. Neuropsychological and functional imagery data have suggested that each hemisphere (at the level of temporo-parietal junctions-TPJ) could play a key role in spatial frequency processing: The right TPJ should predominantly be involved in low spatial frequency (LFs) analysis and the left TPJ in high spatial frequency (HFs) analysis. Nevertheless, this functional hypothesis had been inferred from data obtained when using the hierarchical form paradigm, without any explicit spatial frequency manipulation per se. The aims of this research are (i) to investigate, in healthy subjects, the hemispheric asymmetry hypothesis with an explicit manipulation of spatial frequencies of natural scenes and (ii) to examine whether the 'precedence effect' (the relative rapidity of LFs and HFs processing) depends on the visual field of scene presentation or not. For this purpose, participants were to identify either non-filtered or LFs and HFs filtered target scene displayed either in the left, central, or right visual field. Results showed a hemispheric specialization for spatial frequency processing and different 'precedence effects' depending on the visual field of presentation.     

An assessment of response bias for the same-different task: implications for the single-interval task

Two auditory amplitude discrimination experiments were conducted using the same-different experimental design. Observer bias was manipulated, in the first experiment, by varying payoff matrices and, in the second, by varying prior probabilities of signal presentation. Five levels of bias manipulation and four levels of difficulty were employed in each experiment. Each observer received all combinations of bias manipulation and difficulty, but with only one of these combinations within each block of trials. Nine indices of bias were assessed by simultaneously fitting isosensitivity and isobias functions to the data and by fitting isobias functions only. Although none of the indices tested provided an exceptionally good fit to the data, two indices stood out from the rest. These were c*sd and ci, indices with isobias contours similar in shape to those for the c index derived from the yes-no task.     

Classical Delay Eyeblink Conditioning in in 4- and 5-Month-Old Human Infants

Abstract-Simple delay classical eyeblink conditioning, using a tone conditioned stimulus (CS) and airpuff unconditioned stimulus (US), was studied in cross-sectional samples of 4- and 5-month-old healthy, full-term infants. Infants received two identical training sessions, 1 week apart. At both ages, infants experiencing paired tones and air-puffs demonstrated successful conditioning over two sessions, relative to control subjects who had unpaired training. Conditioning was not evident, however, during the first session. Two additional groups of 5-month-olds received varied experiences during Session 1, either unpaired presentations of the CS and US or no stimulus exposure, fol-lowed by paired conditioning during Session 2. Results from these groups suggest that the higher level of conditioning observed following two sessions of paired conditioning was not the result of familiarity with the testing environment or the stimuli involved but, rather, the result of retention of associative learning not expressed during the first conditioning session.     

Visual acuity improvement following fading and feedback training—I. Comparison of myopic and emmetropic volunteers

18 myopes and 18 emmetropes were randomly assigned in pairs to either Fading and Feedback training or a no-treatment control condition. The emmetropes were fitted with plus lenses equivalent to the spherical correction of the paired myope to simulate myopic visual acuity. Extensive visual acuity measures were obtained pre- and post-training. Data analyses indicated significant increases in recognition visual acuity for trained subjects, compared to no-treatment controls. The myopia/emmetropia variable did not interact with training even though there were noticably greater increases in visual acuity for trained myopes compared to the other conditions. Resolution visual acuity did not change as a function of training. These data are discussed in terms of their implications for better understanding the mechanisms responsible for visual acuity increases following behavioural training.     

Women's Descriptions of Drinking in Bars: Reasons and Risks

Fifty-two women bar drinkers participated infocus group discussions about women's reasons fordrinking, victimization experiences, and behaviors thatinfluence risk for victimization, in bars. The majority of the participants were White (67.3%),one-third were Black (30.8%), and one was NativeAmerican. Qualitative data analytic techniques were usedto assess the content of these discussions. Womendescribed distinct reasons for going to bars and providednumerous accounts of aggression they had witnessed orexperienced associated with this setting. Depictions ofphysical violence ranged from having an object thrown at them or being pushed, to accounts ofrape and attempted murder. These women also describedobservable changes in other women's behavior followingalcohol consumption, and how these behaviors increase risk for victimization in bars. The qualitativefindings are discussed in terms of what they tell usabout women bar drinkers and the insight theyprovide fordesigning future studies and interventions that focus on education and prevention.     

The effects of gender,ethnicity, and a close relationship theme on perceptions of persons introducing a condom

A vignette methodology was used to examineperceptions of condom introducers on sixcondom-relevant,multi-item scales (Nice, Exciting, Sexually Attractive,Promiscuous, Good Relationship Partner,Unpersonable/Personable) in a university student sample of 133 MexicanAmericans and 110 Whites. Data were analyzed in a 2(gender of participant) ×2 (gender of condomintroducer) ×3 (low acculturated Mexican American,high acculturated Mexican American, White) ×2(presence/absence of close relationship theme) analysisof variance and covariance. Women rated condomintroducers significantly higher than men on the Nicescale, female condom introducers were rated significantly higherthan male condom introducers on the Nice scale, andcondom introducers who expressed a care andresponsibility theme while introducing a condom wererated significantly higher on the Nice scale than those whoexpressed no theme. The female condom introducer wasrated significantly higher than the male condomintroducer on the Exciting scale. Condom introducers whoexpressed a care and responsibility theme were ratedsignificantly higher than those who expressed no themeon the Good Relationship Partner scale. In a two-wayinteraction between gender of participant and gender of condom introducer, men rated the femalecondom introducer significantly higher than women on thePromiscuous scale. In another two-way interactionbetween gender of condom introducer and ethnicity, low acculturated Mexican Americans rated the femalecondom introducer significantly higher than the malecondom introducer on the Promiscuous scale. Lowacculturated Mexican Americans rated the condomintroducer significantly higher than Whites on theSexually Attractive scale. There were no significantmain or interaction effects of the independent variableson the Unpersonable/Personable scale.