Using robots to model animals: a cricket test

The sensorimotor problems faced by animals and by robots have much in common, yet identifying this similarity has so far led to very few successful attempts to implement specific biological neural control structures on robots. One major limitation is that understanding of the biological mechanisms is insufficient for straightforward installation. However, using robots as a method of physically modeling animal systems can potentially contribute to our understanding of these mechanisms. This approach is employed in an investigation of phonotaxis (sound-seeking) in crickets. The process of building a robot forms the basis of a critical evaluation of the neuroethological evidence about the cricket, and generates an alternative hypothesis to explain this evidence. The explanatory power of this hypothesis is explored by testing and analyzing the behaviour of the robot that embodies it. The robot behaved like the cricket, competently and robustly finding its way to a specific sound source under a variety of conditions. It is argued that the methodology is more appropriate than symbolic simulation for the kinds of problems raised in the investigation of sensorimotor behaviour in animals and robots.     

The value of pulse oximetry during the performance of a forced spirometry maneuver

Given that forced spirometry is the main routine exploration in any laboratory of pulmonary functional assessment, we have analyzed the behaviour of O2 arterial saturation (SaO2) during such maneuver in patients with airflow chronic obstruction (AFCO), in order to verify any potential alterations. We have studied three groups of patients: Group A, control, 17 healthy subjects; group B, 18 patients with AFCO and initial saturation higher than 90%; group C, 15 patients with AFCO and saturation equal to or lower than 90%. Total duration of the maneuver was significantly higher in groups B and C compared with the control group (p < 0.001). In groups A and B, we did not observed any significant reductions in SaO2 with respect to the initial value, although we did observed such differences in group C (p < 0.001). None of the patients presented a subjective clinical disorder, although the absence of both complexity and risk suggest the convenience of including the oximetry as an additional parameter when conducting a forced spirometry in patients with AFCO and respiratory failure.     

Which are the stimuli in facial displays of anger and happiness? Configurational bases of emotion recognition.

Two studies examined the hypothesis that geometric patterns in the facial expressions of anger and happiness provide information that permits observers to recognize the meaning of threat and warmth. A 1st study sought to isolate the configural properties by examining whether large-scale body movements encode affect-related meanings in similar ways. Results indicated that diagonal and angular body patterns convey threat, whereas round body patterns convey warmth. In a 2nd study, a set of 3 experiments using models of simple geometric patterns revealed that acute angles with downward pointing vertices conveyed the meaning of threat and that roundedness conveyed the meaning of warmth. Human facial features exhibit these same geometric properties in displays of anger and happiness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial retrieval processes in the recovery of order information.

The retrieval of temporal order and item information from short-term memory (STM) are examined with the cued-response speed–accuracy trade-off (CR-SAT) procedure and a complementary reaction time (RT) task. The retrieval of order information was examined with a 2-alternative forced-choice (2AFC), relative judgment of recency (JOR) task. Analyses of the pattern of mean RT, RT accuracy, and the overall shape of the RT distribution for correct JORs suggest that order information is retrieved by a serial retrieval mechanism. Analyses of SAT retrieval functions confirm that order information is retrieved by a recency-based, serial retrieval process. These results contrast with previous SAT analyses of STM item recognition (B. McElree and B. A. Dosher, see record 1990-09049-001), which indicate that item information is retrieved by a parallel or direct-access mechanism. The dissociation between item and order information retrieval was further documented in a 2AFC item recognition SAT study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response styles and the duration of episodes of depressed mood.

Examined the relationship between ruminative and distracting styles of responding to depressed mood and the duration of mood. 79 Ss kept accounts of their moods and responses to their moods for 30 consecutive days. The majority of Ss (83%) showed consistent styles of responding to depressed mood. Regression analyses suggested that the more ruminative responses Ss engaged in, the longer their periods of depressed mood, even after taking into account the initial severity of the mood. In addition, women were more likely than men to have a ruminative response style and on some measures to have more severe and long-lasting periods of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval dynamics of priming in recognition memory: Bias and discrimination analysis.

We investigated semantic priming effects on item recognition from short (8-word) lists in one reaction-time (RT) and three interruption speed–accuracy trade-off (SAT) experiments. SAT priming conditions included modest (0.35-s) prime durations; prime as a final list member; and long (1.5-s) prime durations with special instructions. Analyses tested for constant increment (bias) priming (an equivalent increase in both hits and false alarms) and enhanced discrimination priming (differential priming for targets and lures). Constant increment (bias) priming was ubiquitous, but some subjects showed enhanced early discrimination in restricted conditions. In constant increment (bias) priming, the semantic relations between prime and test either additively increase familiarity or lower criterion. Only enhanced discrimination must imply an interaction between the prime and the retrieval process, due to either interaction or use of compound cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neonatal habituation and dishabituation to tactile stimulation during sleep.

Two experiments examined habituation and dishabituation of behavioral responding to repeated presentations of a tactile stimulus (brush stroke) in 48 newborns during the 1st epoch of active-quiet sleep following a feeding. Exp I demonstrated habituation to a repeatedly presented brush stroke to the ear but failed to demonstrate dishabituation (i.e., response recovery) to the original brush stroke following an intense auditory stimulus (86 dB rattle sound). A post hoc control group showed that the intense auditory stimulus had suppressed subsequent responding to the tactile stimulus. Exp II replicated the habituation phase of Exp I and demonstrated response recovery to stimulation at a novel tactile site and to an auditory probe. Results indicate that the habituation paradigm used in infancy research could be successfully extended to the tactile modality. It is also suggested that prior auditory stimulation, but not prior tactile stimulation, might direct attention away from a subsequently presented tactile stimulus. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship of gender and marital status with symptomatology in psychotic patients.

Examined the relationship of gender and marital status with ratings of symptoms in 882 psychiatric patients (521 males and 361 females) diagnosed as schizophrenic on the DSM-II. Analysis of total symptom scores revealed an interactive effect of gender and marital status; married women (mean age 37.02 yrs) had the highest total symptom scores, whereas married men (mean age 34.88 yrs) had the lowest. Factor analysis of the symptom ratings yielded 9 symptom factors: Ideational Symptoms, Anhedonia, Cognitive Disorientation, Suicidal Tendencies, Vegetative Symptoms, Hostility, Anxiety, Narcotic Abuse, and Alcohol Abuse. Factor scores were then computed to investigate possible gender and marital status differences in symptom pattern. Different profiles of symptoms as a function of gender were found. Females scored higher on the factors defined by affective symptoms, namely, Anhedonia, Suicidal Tendencies, and Vegetative Symptoms. They also scored higher on Cognitive Disorientation. The only factor on which males scored higher than females was Alcohol Abuse. Results are discussed in light of selection and protection theories of the relationship between marital status and mental health. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)