Can the memory enhancement of the survival judgment task be explained by the elaboration hypothesis?: Evidence from a memory load paradigm1

Many reports have described a survival judgment task that requires participants to judge words according to their relevance to a survival situation, eliciting better recall than that obtained in other judgment tasks (e.g., semantic or self‐judgment tasks). Two explanatory hypotheses (the adaptive hypothesis and the elaboration hypothesis) have been proposed. Here we used the memory load paradigm to investigate whether the adaptive hypothesis or the combination hypothesis can better account for the memory enhancement of the survival judgment task. We used a survival judgment task and an autobiographical recall task with the condition of no memory load or memory load. The 48 participants performed four encoding conditions (memory load—survival, no memory load—survival, memory load—autobiographical, and no memory load—autobiographical). The results showed that memory enhancement of the survival judgment task occurred only in the no memory load condition, but not in the memory load condition. Our results support the elaboration hypothesis. We also discuss the validity of the elaboration hypothesis and future directions to be pursued in this research field.     

N400 and P600 or the Role of the ERP Correlates in Sentence Comprehension: Some Applications to the Italian Language

In the present study, event-related brain potentials (ERPs) were applied to the study of language comprehension in the Italian language. The ERPs were recorded from 10 electrodes while the participants read (Experiment 1) or listened (Experiment 2) to sentences containing semantic or syntactic anomalies. Final words that were inconsistent with the sentence context elicited a negative wave at about 400 ms poststimulus that was more concentrated in the posterior sites of the scalp, whereas final words that were incongruous with the grammatical structure (subject-verb nonagreement) elicited a positive wave at about 600 ms poststimulus that was homogeneously distributed on the scalp. The authors found no differences based on the perceptual modality of the stimulus (visual or auditory), nor did they find different ERP correlates as a function of task relevance (explicit-implicit task induction). The available evidence indicated that the ERP response to semantic anomalies was at least partially distinct from the ERP response to syntactic anomalies, and that a syntactic parser is a plausible process included in sentence comprehension. The two semantic and syntactic effects appear as automatic processes of the decoding of the anomalies and also modality-independent processes. Cross-linguistic applications are considered in the general discussion.     

A Case of Synaesthesia

Two experiments employed Potential Performance Theory (PPT) to correct for inconsistency in a speeded task. In Experiment 1, a search task was employed whereby participants searched for a target letter among distracters. In Experiment 2, the search task was more complex and naturalistic—participants searched for enemy weapons in aerial photographs. Not surprisingly, the results revealed that longer search times led to greater accuracy. However, this improvement was due only in part to improved search strategies. Much, if not most, of the improvement was due to increased consistency. The authors demonstrate and discuss some of the advantages to be gained by considering a speeded task within the context of a clear and mathematically precise theory (PPT).     

Perceptual Effect on Motor Learning in the Serial Reaction-Time Task

Although the Serial Reaction-Time Task has been an effective tool in studying procedural learning, there is still a debate as to whether learning in the task is effector-based, stimulus-based, or response-based. In this article, the authors contribute to this debate by contrasting response- and stimulus-based learning by manipulating them selectively and simultaneously. Results show that (a) participants learned response sequences in the absence of stimulus-specific perceptual sequence information but (b) not stimulus sequences without corresponding response information. In a third condition, response sequence and stimulus frequency information were in conflict, and each effect decreased learning in the other domain. Overall, our findings show that learning in these tasks is primarily motor-based, but it is also constrained by relatively salient perceptual information. Together with earlier findings in the literature, the findings also suggest a task and stimulus-arrangement-specific interaction between motor and perceptual learning, where relevance and salience of the specific information plays a crucial role.     

Hearing-Loss Effects on a Procedural Task Sequence

40 deaf and 40 hearing children representing 2 age groups were blindfolded and presented with 3 high-relief finger mazes of increasing complexity. It was found that young deaf children performed the most difficult task more efficiently than comparable hearing children. Contrary to previous findings, hearing children showed no advantage over deaf children on any of the three tasks as a result of their supposed greater facility with verbal conceptual mediators. The results were interpreted as supporting the idea that deaf children compensate for their auditory lack and verbal deficiency by developing problem solving skills that maximize sensitivity to other sensory modalities.     

Transfer Variables in Tracking Skills

In the present work the effect of two task variables on transfer were studied: shape of the track-circular or triangular; and target speed-constant or variable. One or both of these variables was changed on transfer. Experimental conditions were (a) 10 preshift and 10 post-shift trials, and (b) 20 single-trial alternations of two tasks. 22 groups of 12 Ss each were tested. Condition (a) showed positive transfer with single variable change and zero or negative transfer with simultaneous change in two variables, and condition (b) annulled all transfer effects. Results are discussed in terms of commonality between tasks and receptor and perceptual anticipation.     

A Test of the Adams-Creamer Decay Hypothesis for the Timing of Motor Responses

The Adams-Creamer hypothesis states that S uses the decay of proprioceptive feedback from an early portion of a movement to cue a timed response at some later time. This hypothesis was tested by creating passive left-arm movement in one group and withholding it from another, and having Ss make a right-hand response when exactly 2.0 sec. had elapsed since the end of the movement Ss with left-arm feedback had less absolute and algebraic error, and greater within-S consistency than did the no-movement control Ss and, when KR was withdrawn, Ss with left-arm movement regressed less than did Ss without the left-arm movement, which provided 2 lines of support for the decay hypothesis.     

The Effect of Interpolated Motor Activity on the Short-Term Retention of Movement Distance and End-Location

The effect of an interpolated movement on the recall of a blind, lever-positioning movement was assessed separately for the reproduction cues of distance and end-location. Both cues showed the context effect of assimilation, that is, the end-location of the interpolated movement caused directional biasing of the algebraic or constant error (CE) for location reproduction while the length of the interpolated movement caused similar directional biasing for distance reproduction. Variability about algebraic error (VE) was used to assess forgetting. There was no change in VE for location reproduction, and an increase in VE for distance reproduction was limited to the relatively large movements. Thus, an interpolated movement that does not have to be remembered does not cause interference with the retention of location information, but does cause some interference with the retention of distance information. The findings are discussed in relation to a model of motor short-term memory which incorporates both CE and VE.     

Effects of Classically Differentiated Supplementary Feedback Cues on Tracking Skill

Although previous studies had shown that classical predifferentiation of green (CS-j and red (CS+) cues enabled them to facilitate tracking performance when used as supplementary indicators of correct and incorrect responses respectively, the studies were inconclusive concerning specific conditional properties versus nonspecific arousal consequences of the cues. A sample of 108 Ss was exposed to the same predifferentiation procedure, but then were subgrouped in terms of the kind of feedback signal received in tracking (no signal, red only, green only, both signals). A nonspecificity theory predicts subgroup equality of tracking performances while specificity theory predicts the dependence of performance level on the kind of signal received. Results corroborated previous findings and the view that tracking effects were reasonably attributable to the transfer of specific stimulus functions generated in the differentiation trials.     

Exposure to Repetitive Tasks Induces Motor Changes Related to Skill Acquisition and Inflammation in Rats

The authors elucidate exposure-response relationships between repetitive tasks, inflammation, and motor changes with work-related musculoskeletal disorders. Using a rat model of reaching and handle pulling, they examined effects of performing a high-repetition, low-force (HRLF); low-repetition, high-force (LRHF); or high-repetition, high-force (HRHF) task (2 hr/day, 3 days/week, 12 weeks) on reach rate and force, percentage of successful reaches, duration of participation, and grip strength. Reach rate and reach force improved with HRLF, and percentage success increased in all groups in Week 9, and in HRLF and HRHF in Week 12, indicative of skill acquisition. Duration and grip strength showed force-dependent declines with task performance. A subset of HRHF rats received ibuprofen in Weeks 5–12. Ibuprofen significantly improved reach rate, reach force, and duration in treated rats, indicative of an inflammatory influence on reach performance. Ibuprofen improved percentage of successful reaches in Week 9, although this increase was not sustained. However, declines in grip strength, a nocifensive behavior, were not prevented by ibuprofen. Examination of cervical spinal cords of untreated and ibuprofen treated HRHF rats showed increased IL-1beta, an inflammatory cytokine, in neurons. These findings suggest that only a preventive intervention could have addressed all motor declines.