Location and frequency cues in auditory selective attention

The roles of frequency and location cues in auditory selective attention were investigated in a series of experiments in which target tones were distinguished from distractors by frequency, location, or the conjunction of frequency and location features. When frequency separations in high-rate tone sequences were greater than 1 octave, participants were fastest at identifying targets defined by frequency and were sometimes faster at identifying conjunction than location targets. Frequency salience diminished as filtering demands were reduced: At long interstimulus intervals (> 2.0 s), performance was superior in location conditions. The results suggest that frequency may play a role in auditory selective attention tasks analogous to the role of spatial position in visual attention.     

Further exploration memory bias in compulsive washers

The aim of the present study was to replicate Radomsky and Rachman's findings on memory bias in obsessive-compulsive disorder (OCD), using the same procedure but an increased sample size, more specific control groups, and a full analysis of contamination attribution data. Sixteen OCD-washers, 16 OCD-checkers, 16 social phobic patients and 16 non-anxious controls were presented with 50 'clean' or 'dirty' objects. After this incidental encoding phase, participants were asked to freely recall the objects, to rate their anxiety when almost touching each object, and, finally, to attribute each object to one of the two contamination conditions ('clean' or 'dirty'). Verbal episodic memory was also assessed with the California Verbal Learning Test. The results indicate that, contrary to Radomsky and Rachman's findings, OCD-washers did not differ from the other participants in their memory for 'clean' and 'dirty' objects. However, the OCD-washers recalled more accurately the 'dirty' source of contamination than the 'clean' source. This result was specific to the OCD-washers, and suggests a memory bias for contextually threatening information. The differences between our findings and those published by Radomsky and Rachman's are discussed.     

Study of the energy correlates in the learning of a complex self-paced cyclical skill

This study examines changes in movement parameters and energy expense during the learning of a cyclical task performed on a “ski simulator”. Five subjects performed five training sessions (each of four 4-minute learning periods separated by a 4-minute rest) and then took a post-test one week later. The instructions were to make movements which were “as wide and frequent as possible”. The subjects were filmed on videotape and their oxygen intake was measured. Movement amplitude, movement frequency, oxygen intake, and a “movement cost” index were calculated. The results indicated a significant increase in movement amplitude and oxygen intake and a decrease in movement cost. The movement frequency of all subjects tended towards the same final value. Two simultaneous changes could occur, with large individual differences: an increase in energy expense due to the increase in the amount of work done, a decrease in energy expense due to the increase in movement economy.     

Same-hand and different-hand finger pairings in two-choice reaction time: presence or absence of response competition?

Several two-choice reaction time experiments have compared conditions in which the two possible responses were from the same hand (same-hand pairing) or from different hands (different-hand pairing). Studies that used only the two relevant fingers on response keys reported shorter reaction times for the different-hand pairing. In other studies, two additional but irrelevant fingers were also in contact with response keys. These fingers were irrelevant in the sense that they never were required to respond. With this procedure, equivalent reaction times were found between same-hand and different-hand pairings. Reeve and Proctor (1988) recently have argued that using only two fingers results in response competition between the two fingers from the same hand, yielding shorter reaction times for the different-hand pairing condition. In contrast, when four fingers are placed on response keys, response competition should be absent for both the same-hand and the different-hand pairing conditions, resulting in equivalent reaction times. In the present work, reaction times associated with the same-hand pairing condition remained unchanged, irrespective of the number of fingers positioned on keys. In the different-hand pairing condition, reaction times were found to be longer when four fingers were used than when only two fingers rested on response keys. Thus, when four fingers are placed on keys, response competition appears to be present rather than absent. Other results showed that the response competition found in the different-hand pairing condition decreases with practice.     

Are movements/proprioception effective time-keeping mediators? The input hypothesis re-visited

Based upon the experimental literature surveyed, and given that time-keeping accuracy (i.e., constant error, absolute error, beneficial anticipation) is the appropriate performance dimension to consider, there appears to be virtually no support for the speculation that proprioception serves as an effective mediator for conscious time-keeping judgements. For the most part, individuals afforded movements during the interval to be timed did not perform significantly more precisely than did those people deprived of such time-filling movements, nor did they consistently estimate time with significantly less variability. On this basis, and because other predictions of the Input Hypothesis examined herein (left/right hand covariance, practice by movement group interaction and effect of different levels of proprioception) were not experimentally supported, the validity of the Input Hypothesis was rejected.     

Assessing the Approximate Number System: no relation between numerical comparison and estimation tasks

Whether our general numerical skills and the mathematical knowledge that we acquire at school are entwined is a debated issue, which many researchers are still striving to investigate. The findings reported in the literature are actually inconsistent; some studies emphasized the existence of a relationship between the acuity of the Approximate Number System (ANS) and arithmetic competence, while some others did not observe any significant correlation. One potential explanation of the discrepancy might stem from the evaluation of the ANS itself. In the present study, we correlated two measures used to index ANS acuity with arithmetic performance. These measures were the Weber fraction (w), computed from a numerical comparison task and the coefficient of variation (CV), computed from a numerical estimation task. Arithmetic performance correlated with estimation CV but not with comparison w. We further investigated the meaning of this result by taking the relationship between w and CV into account. We expected a tight relation as both these measures are believed to assess ANS acuity. Crucially, however, w and CV did not correlate with each other. Moreover, the value of w was modulated by the congruity of the relation between numerical magnitude and non-numerical visual cues, potentially accounting for the lack of correlation between the measures. Our findings thus challenge the overuse of w to assess ANS acuity and more generally put into question the relevance of correlating this measure with arithmetic without any deeper understanding of what they are really indexing.     

The Impact of Decision Timing on the Effectiveness of Leaders’ Apologies to Repair Followers’ Trust in the Aftermath of Leader Failure

Purpose

The aim of the present research was to investigate how a negative decision outcome generated by a leader in a hasty, timely, or delayed manner impacts upon the need for, and the effectiveness of apologies to restore followers’ trust.

Design/Methodology/Approach

Data were collected using five studies in which the effects of timing of an incorrect decision on the trust repair process were investigated.

Findings

In the aftermath of a leader’s failure, followers experienced a delayed incorrect decision as a more severe transgression than a hasty or a timely incorrect decision. This effect was mediated by procedural fairness concerns (Study 1). The present findings also revealed an interesting paradox. Specifically, in the delayed condition followers expressed the highest need for an apology (Studies 2 and 3), but at the same time expected an apology to be less effective for enhancing trustworthiness than in the timely and the hasty condition (Study 3). Moreover, we also showed that the actual provision of an apology was effective for restoring both trustworthiness (Study 4) and trust (Studies 4 and 5) in the timely and the hasty condition, but ineffective in the delayed condition.

Implications

The present research shows that when the outcome of a decision is uncertain, it is better to make a decision (too) soon rather than (too) late.

Originality/Value

Despite the ubiquity of timing errors in daily life, our studies are the first to focus on the role of timeliness of decisions in the trust repair process.

     

Toward a neurophysiological theory of auditory stream segregation

Auditory stream segregation (or streaming) is a phenomenon in which 2 or more repeating sounds differing in at least 1 acoustic attribute are perceived as 2 or more separate sound sources (i.e., streams). This article selectively reviews psychophysical and computational studies of streaming and comprehensively reviews more recent neurophysiological studies that have provided important insights into the mechanisms of streaming. On the basis of these studies, segregation of sounds is likely to occur beginning in the auditory periphery and continuing at least to primary auditory cortex for simple cues such as pure-tone frequency but at stages as high as secondary auditory cortex for more complex cues such as periodicity pitch. Attention-dependent and perception-dependent processes are likely to take place in primary or secondary auditory cortex and may also involve higher level areas outside of auditory cortex. Topographic maps of acoustic attributes, stimulus-specific suppression, and competition between representations are among the neurophysiological mechanisms that likely contribute to streaming. A framework for future research is proposed.