Effect of manipulating the risetime of an acoustic stimulus on two protective reflexes: cardiac defense and motor startle

Effect of manipulating the risetime of an acoustic stimulus on two protective reflexes: cardiac defense and motor startle. The risetime is a parametric characteristic of the eliciting stimulus frequently used to differentiate among psychophysiological reflexes. The aim of the present study was to examine the effect of manipulating the risetime of an acoustic stimulus on two protective reflexes: cardiac defense and motor startle. 100 participants underwent a psychophysiological reactivity test to five presentations of an intense acoustic stimulus (105 dB white noise) under one of five risetime conditions: 0, 24, 48, 96, and 240 ms. Total energy of the stimulus was controlled by increasing the base duration of the stimulus (1000 ms) by one third of the risetime. Results showed that risetime significantly affected motor startle but not cardiac defense. Startle amplitude decreased linearly with increasing risetime after 24 ms. On the other hand, repetition of the stimulus significantly affected cardiac defense but not motor startle. These results question the traditional differentiation between startle and defense based on risetime.     

Item selection rules in a Computerized Adaptive Test for the assessment of written English

Item selection rules in a Computerized Adaptive Test for the assessment of written English. e-CAT is a Computerized Adaptive Test for the evaluation of written English knowledge, using the item selection rule most commonly employed: the maximum Fisher information criterion. Some of the problems of this criterion have a negative impact in the estimation accuracy and in the item bank security. In this study, the performance of this item selection rule is compared, by means of simulation, with two other rules: selecting the item with maximum Fisher information in an interval (Veerkamp y Berger, 1997) and a new criterion, called "maximum Fisher information in an interval with geometric mean". In general, this new rule shows smaller measurement error and smaller item overlap rates. It seems, thus, recommendable, as it allows the simultaneous improvement of estimation accuracy and the maintenance of the item bank security of e-CAT.     

Training higher education students in mathematics learning strategies

The present research focuses on the design and testing of a training program in learning strategies for Mathematics in Higher Education students. This research displays a quasiexperimental-sequential design with a non-equivalent control group. The research aims at revealing the effect of this training program both on the student's competence in learning strategies and on academic performance in this curricular area. There have been 176 students taking part in this research (74 students forming the experimental group and 72 forming the control group). The obtained results permit to assess the program efficiency as regards both trained strategies handling and specific performance improvement.     

Stress in mothers of individuals with autistic spectrum disorders

The aim of this study was to analyze maternal stress in families of individuals with autism. We proposed a multi-factorial and global model based on the Double ABCX model of family stress (McCubbin & Patterson, 1983) in which, the factor aA (stressor) interacts with bB (social support) and cC (perception of stress or, in our study, sense of coherence, SOC) to produce the dependent factor xX (level of stress). Thirty-nine mothers with children diagnosed on Autistic Spectrum disorders completed four questionnaires relating to the factors. The data were statistically analyzed using path analysis. The results showed that the empirical data fitted the theoretically proposed model well. There existed a direct and positive relationship between stressor and stress. Social support and SOC had a direct and negative relationship to stress, and functioned as modulating variables.     

Development and validation of a psychometric instrument for the assessment of depression in the elderly

Depression is one of the main the psychological disorders in the gerontological population. However, in many cases the depressive alterations can go unnoticed or masked by the elderly s somatic complaints; or even the depressive symptoms can be ascribe to the own aging process. Moreover, it has to be added that old patients tend not to request help to specialised mental health centres. Therefore, the correct diagnosis of the depressed elderly's emotional problems becomes into a question of extraordinary importance. In this work is presented a new specific instrument for the evaluation of depression in the elderly people which has, among other characteristics, the advantage of requiring a little time to its application and a low knowledge on psychopathology. The initial results show an extraordinary sensitivity and specificity regarding to DSM-IV-TR criteria. Nevertheless, further studies with a higher number of clinical populations are necessary to confirm and enlarge these preliminary results.     

A Chilean version of the Efficient Personality Questionnaire for Adolescents

This investigation aims at adapting the test for Efficient Personality in educational contexts to Chilean reality. This instrument measures the construct efficient personality , made up of four levels of the self: strengths, requests, challenges and relationships. The original version has 58 items. In order to adapt it to our reality, 30 items were modified. The instrument was applied to a sample of 594 third and fourth secondary level students from four educational institutions of Vi?a del Mar. The new version of the instrument (23 items) presents a .85 reliability coefficient. The factorial analysis shows a structure of four basic factors which explain 50.42 % of the total variance. These factors, which are very similar those proposed in the original instrument, are named as academic self realization, social self realization, solving efficiency, and self steem. The second order factors analysis reveals a single factors structure that explains 43,28 % of the total variance, thus confirming the presence of the only factor that would correspond to the efficient personality construct presented.     

The entorhinal cortex plays a role in extinction

In this study, we analyzed the participation of the entorhinal cortex in extinction of a learned aversive response. Rats with infusion cannulae aimed to the entorhinal cortex were trained in a one-trial step-down inhibitory avoidance task (IA) and submitted to four consecutive daily test sessions without the footshock, a procedure that induced extinction of the conditioned response in control animals. When infused into the entorhinal cortex immediately after the first extinction session at doses able to block consolidation of IA memory, the NMDA receptor antagonist, AP5 (25 nmol/side), the inhibitor of protein synthesis anisomycin (300 nmol/side) and the inhibitor of CaMKII, KN-93 (10 nmol/side), but not the MEK1/2 inhibitor PD-98059 (5 nmol/side) hindered extinction of the IA response. The same results were obtained when the interval between the first and second test session was 48 instead of 24h. The data indicate that normal functionality of the NMDA receptors, together with CaMKII activity and protein synthesis are necessary in the entorhinal cortex at the time of the first test session to generate extinction. Our results also suggest that the ERK1/2 pathway does not play a role in this process.     

The rhinal cortex: 'gatekeeper' of the declarative memory system

Almost all studies probing neural activity underlying the declarative memory system in humans have investigated either memory encoding or retrieval. Here, however, we suggest integrating encoding and retrieval operations into a single operation executed by the rhinal cortex. The more familiar an item is, the less rhinal processing it requires and the less vigorously it is encoded into memory. Given the anatomical position and the functional properties of the rhinal cortex, this operation fulfills an essential task: it optimally allocates limited encoding resources away from familiar information and towards novel information. We propose a rhinal processing stage that optimizes the declarative memory system by fully integrating encoding and retrieval operations into a single 'gatekeeper' operation.     

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org

Call for Papers

Third International Conference on Spatial Cognition: “Dynamics in Spatial Interactions”. Rome - Perugia, Italy: September 12th–15th 2006. www.icsc2006.org - committee@icsc2006.org