论外部的心理物理学和内部的心理物理学

Fechner提出的内部的心理物理学函数关系在解释实验事实时有困难。基于实验 ,提出内部的心理物理学的一个新的函数关系。     

Simultaneous independent threshold estimates: Multiple PEST

An adaptive threshold estimation procedure, PEST, has been extended to track sensitivity to many independent signals simultaneously within a single experimental run. This paradigm has been implemented on a PDP-8/S computer, and enables investigation of a number of otherwise experimentally intractible substantive problems. The logic of the new experimental paradigm is described, and some examples are given of its use in auditory research. Results of some computer simulations show the relative efficiency of the procedure and evaluate alternative ways to summarize data.     

Direct estimates of processing delays in the attentional blink

 When two targets (T1 and T2) are presented in rapid succession, identification of T2 is often impaired (attentional blink: AB). The two-stage model accounts for the AB deficit by assuming that: (a) T2 is delayed in Stage 1 while Stage 2 is busy processing T1, and (b) T2 is vulnerable to masking while delayed. We report converging evidence for the model by evaluating these assumptions independently of the AB deficit itself. The results show that: (a) response times for T2 identification decreased as the lag between T1 and T2 was increased; (b) response times for T2 decreased across lags only if T1 was masked; and (c) accuracy of T2 identification increased as the stimulus-onset asynchrony between T2 and the trailing mask was increased. Received: 4 February 1999 / Accepted: 26 July 1999     

Investigating the role of attentional resources in the irrelevant speech effect

Irrelevant words can be disruptive to performance, and the frequency of usage of the irrelevant words has affected the magnitude of such disruption (Buchner &; Erdfelder, 2005). The finding of word frequency differences in the magnitude of the irrelevant speech effect (ISE) implicated a role for attentional processes. Using a different conceptualization of attention, researchers have found that individual differences in working memory capacity did not predict the magnitude of the ISE, which questioned the role of attentional control (Beaman, 2004; Sörqvist, 2010). The current study investigated aspects of the construct of attention and the ISE, using both individual and developmental difference approaches. Results showed no significant difference between serial recall performances in the presence of high or low word frequency distractors. Furthermore, effects of working memory capacity differences were not found, but children displayed a larger ISE than college students. The weight of the evidence appears against an attentional resource view of the ISE.     

Psychophysics of the McGurk and other audiovisual speech integration effects

When the auditory and visual components of spoken audiovisual nonsense syllables are mismatched, perceivers produce four different types of perceptual responses, auditory correct, visual correct, fusion (the so-called McGurk effect), and combination (i.e., two consonants are reported). Here, quantitative measures were developed to account for the distribution of the four types of perceptual responses to 384 different stimuli from four talkers. The measures included mutual information, correlations, and acoustic measures, all representing audiovisual stimulus relationships. In Experiment 1, open-set perceptual responses were obtained for acoustic /bɑ/ or /lɑ/ dubbed to video /bɑ, dɑ, gɑ, vɑ, zɑ, lɑ, wɑ, eɑ/. The talker, the video syllable, and the acoustic syllable significantly influenced the type of response. In Experiment 2, the best predictors of response category proportions were a subset of the physical stimulus measures, with the variance accounted for in the perceptual response category proportions between 17% and 52%. That audiovisual stimulus relationships can account for perceptual response distributions supports the possibility that internal representations are based on modality-specific stimulus relationships.     

Investigating the effects of tic suppression on premonitory urge ratings in children and adolescents with Tourette's syndrome

Tics represent a complex class of behaviors that have a neurobiological origin and are influenced by factors both internal and external to the individual. One factor that has gained recent attention is the premonitory urge. Contemporary behavioral models suggest that some tics are preceded by aversive somatic urges that increase in severity when tics are suppressed and are attenuated by performance of the tic. It has been proposed that the removal of premonitory urges may strengthen or maintain tics via negative reinforcement. This investigation is the first to empirically evaluate the effect of tic suppression on the premonitory urge phenomenon. Five children and adolescents, ages 8–17 years, participated in the study. Using an ABAB reversal design, tic frequency and subjective premonitory urge ratings were recorded under conditions of free-to-tic baseline (BL) and reinforced tic suppression (differential reinforcement of zero-rate behavior). Results show that four of the five children demonstrated reliable suppression. Of the four children who achieved suppression, three demonstrated a pattern in which subjective urge ratings were higher during suppression than during BL. Results provide preliminary support for the negative reinforcement view of tic function for some children.     

Detection of emotional faces: low perceptual threshold and wide attentional span

In two experiments, prime face stimuli with an emotional or a neutral expression were presented individually for 25 to 125 ms, either in foveal or parafoveal vision; following a mask, a probe face or a word label appeared for recognition. Accurate detection and sensitivity (A') were higher for angry, happy, and sad faces than for nonemotional (neutral) or novel (scheming) faces at short exposure times (25-75 ms), in both the foveal and the parafoveal field, and with both the probe face and the probe word. These results indicate that there is a low perceptual threshold for unambiguous emotional faces, which are especially likely to be detected both within and outside the focus of attention; and that this facilitated detection involves processing of the affective meaning of faces, not only discrimination of formal visual features.     

The effects of the Triple P-Positive Parenting Program on preschool children with co-occurring disruptive behavior and attentional/hyperactive difficulties

Two variants of a behavioral family intervention (BFI) program known as Triple P were compared using 87 preschoolers with co-occurring disruptive behavior and attentional/hyperactive difficulties. Families were randomly allocated to enhanced BFI (EBFI), standard BFI (SBFI), or a waitlist (WL) control group. At postintervention both BFI programs were associated with significantly lower levels of parent-reported child behavior problems, lower levels of dysfunctional parenting, and greater parental competence than the WL condition. The EBFI condition was also associated with significantly less observed child negative behavior in comparison to the WL. The gains achieved at postintervention were maintained at 1-year follow-up. Contrary to predictions, the enhanced program was not shown to be superior to the standard program using any of the outcome measures at either postintervention or follow-up. Each of the programs produced significant reductions in children's co-occurring disruptive behavior and attentional/hyperactive difficulties with 80% of the children showing clinically reliable improvement in observed negative behavior from preintervention to follow-up.     

Blinks of the mind: memory effects of attentional processes

If 2 words are presented successively within 500 ms, subjects often miss the 2nd word. This attentional blink reflects a limited capacity to attend to incoming information. Memory effects were studied for words that fell within an attentional blink. Unrelated words were presented in a modified rapid serial visual presentation task at varying stimulus-onset asynchronies, and attention was systematically manipulated. Subsequently, recognition, repetition priming, and semantic priming were measured separately in 3 experiments. Unidentified words showed no recognition and no repetition priming. However, blinked (i.e., unidentified) words did produce semantic priming in related words. When, for instance, ring was blinked, it was easier to subsequently identify wedding than apple. In contrast, when the blinked word itself was presented again, it was not easier to identify than an unrelated word. Possible interpretations of this paradoxical finding are discussed.     

注意控制定势和线索类型在注意捕获中的作用

采用前线索范式, 通过3个实验考察了注意控制定势和线索类型在注意捕获中的作用。实验1要求被试搜索颜色奇异项目标或突现目标, 涉及较弱的注意控制定势, 结果表明, 突现线索在作为匹配线索和不匹配线索时都能捕获注意, 而颜色奇异项线索只有在作为匹配线索时才能捕获注意。实验2要求被试搜索具体特征的红色或白色目标, 使被试建立较强的特征搜索定势, 结果表明, 颜色奇异项线索和突现线索在作为匹配线索时都能捕获注意, 但是在不匹配条件下, 颜色奇异项线索被抑制了, 而突现线索不能捕获注意; 实验3采取go/no-go范式, 要求被试对红色目标进行反应, 对白色目标进行抑制, 并通过设置不同的线索-目标时间间隔来进一步考察注意捕获的机制, 结果表明, 在600 ms间隔下, no-go突现线索被抑制, 而对于go颜色奇异项线索来说, 随着时间间隔的增加, 注意捕获效应减少。结果与相倚捕获假说和抑制独立捕获假说不符, 支持注意转移假说：自上而下的注意控制定势通过把注意从和目标不匹配的特征位置转移发挥作用; 颜色奇异项线索和突现线索的注意捕获机制相同, 但是突现线索相对于颜色奇异项线索来说, 在与目标不匹配的条件下, 更容易捕获注意, 更难被抑制。     

Threshold variability in subliminal perception experiments: fixed threshold estimates reduce power to detect subliminal effects.

In studies of subliminal perception, a threshold for awareness is usually estimated for each S (e.g., the stimulus duration that yields chance discrimination performance). This article shows that if the S's true threshold varies randomly from trial to trial, estimation of a fixed threshold has important consequences. Specifically, the estimated threshold approaches the minimum of the distribution of true thresholds, and the power of an experiment to detect subliminal perception is reduced. Because there is much evidence that true thresholds vary across trials, threshold variability may have seriously weakened previous experiments that tested for subliminal perception. Fortunately, it is possible to estimate the maximum power loss resulting from threshold variability and therefore to design an experiment with acceptable power even in the presence of variability.     

Orientation discrimination across the visual field: size estimates near contrast threshold

Performance in detection and discrimination tasks can often be made equal across the visual field through appropriate stimulus scaling. The parameter E2 is used to characterize the rate at which stimulus dimensions (e.g., size or contrast) must increase in order to achieve foveal levels of performance. We calculated both size and contrast E2 values for orientation discrimination using a spatial scaling procedure that involves measuring combination size and contrast thresholds for stimuli with constant size-to-contrast ratios. E2 values for size scaling were 5.77 degrees and 5.92 degrees. These values are three to four times larger than those recovered previously using similar stimuli at contrasts well above detection threshold (Sally & Gurnsey, 2003). E2 values for contrast scaling were 324.2 degrees and 44.3 degrees, indicating that for large stimuli little contrast scaling (.3% to 2.3% increase) was required in order to equate performance in the fovea and the largest eccentricity (10 degrees). A similar pattern of results was found using a spatial scaling method that involves measuring contrast thresholds for target identification as a function of size across eccentricities. We conclude that the size scaling for orientation discrimination at near-threshold stimulus contrasts is much larger than that required at suprathreshold contrasts. This may arise, at least in part, from contrast-dependent changes in mechanisms that subserve task performance.     

Memory reloaded: Memory load effects in the attentional blink

When two targets are presented in rapid succession, identification of the first is nearly perfect, while identification of the second is impaired when it follows the first by less than about 700 ms. According to bottleneck models, this attentional blink (AB) occurs because the second target is unable to gain access to capacity-limited working memory processes already occupied by the first target. Evidence for this hypothesis, however, has been mixed, with recent reports suggesting that increasing working memory load does not affect the AB. The present paper explores possible reasons for failures to find a link between memory load and the AB and shows that a reliable effect of load can be obtained when the item directly after T1 (Target 1) is omitted. This finding provides initial evidence that working memory load can influence the AB and additional evidence for a link between T1 processing time and the AB predicted by bottleneck models.     

Psychophysics of Remembering: The Discrimination Hypothesis

In a psychophysical approach to remembering, the events to be remembered are discriminated from other possibilities at the time of remembering, and not at the time of encoding or learning. The discrimination is specific to the retention interval at which remembering occurs, as shown by experiments demonstrating that discriminability and response bias are delay–specific. This article discusses a discrimination model for remembering that emphasizes the individual's history of learning about reward payoffs in similar experiences in the past. This model predicts the two characteristics of forgetting functions, initial discriminability and rate of forgetting.     

The effects of progressive sleep loss on a lexical decision task: Response lapses and response accuracy

A lexical decision task was used in a paradigm testing the effects of sleep loss and fatigue on performance during a 72-h period of sleep deprivation. The data were partitioned into categories of response lapses, response accuracy, and the signal detection measures of discriminability (d’) and bias (β). Response lapses increased as a function of sleep loss and were fitted best by a composite equation with a major linear component and a minor rhythmic component. Response accuracy decreased as a function of sleep loss, with the rate of decrease being greater for nonwords than for words. Although d’ was higher for right visual field (RVF), it decreased for both fields almost linearly as a function of sleep deprivation. The rate of decrease for RVF stimulation was greater than for left visual field (LVF) stimulation, β did not change monotonically as a function of sleep loss, but showed strong circadian rhythmicity, indicating that it was not differentially affected by sleep loss per se.     

Investigating temporal properties of covert shifts of visual attention using the attentional walk task

The attentional walk task was used to investigate the temporal properties of covert shifts of attention. Observers shifted attention within arrays of identical items in response to a series of auditory commands and reported the color of the final disk. The density of the arrays and the timing of the shift commands varied. Performance decreased as density increased, and the minimal amount of time needed to shift attention depended on the density of the display, varying from 350 to 750 msec. In addition, the observers were able to maintain attentional focus for at least 3,500 msec without a decline in performance, regardless of density. Thus, although the ability to maintain attention at a given position was found to be independent of the precision with which that location was defined, more precise attentional shifts required more time to execute.     

Psychophysics and the anisotropy of time

In psychophysics, experimental control over the presented stimuli is an important prerequisite. Due to the anisotropy of time, this prerequisite is not given in psychophysical experiments on time perception. Many important factors (e.g., the direction of perceived time flow) cannot be manipulated in timing experiments. The anisotropy of time is a peculiarity, which distinguishes the time dimension from other perceptual qualities.Here I summarize the anisotropy-related differences between the perception of time and the perception of other qualities. It is discussed to what extent these differences might affect results and interpretations in psychophysical experiments. In conclusion, I argue for a ‘view from nowhen’ on the psychophysical study of time perception.     

Auditory attentional capture: effects of singleton distractor sounds

The phenomenon of attentional capture by a unique yet irrelevant singleton distractor has typically been studied in visual search. In this article, the authors examine whether a similar phenomenon occurs in the auditory domain. Participants searched sequences of sounds for targets defined by frequency, intensity, or duration. The presence of a singleton distractor that was unique on an irrelevant dimension (e.g., a low-frequency singleton in search for a target of high intensity) was associated with search costs in both detection and discrimination tasks. However, if the singleton feature coincided with the target item, search was facilitated. These results establish the phenomenon of auditory attentional capture.     

Thinking about muscles: the neuromuscular effects of attentional focus on accuracy and fatigue

Although the effects of attention on movement execution are well documented behaviorally, much less research has been done on the neurophysiological changes that underlie attentional focus effects. This study presents two experiments exploring effects of attention during an isometric plantar-flexion task using surface electromyography (sEMG). Participants' attention was directed either externally (towards the force plate they were pushing against) or internally (towards their own leg, specifically the agonist muscle). Experiment 1 tested the effects of attention on accuracy and efficiency of force produced at three target forces (30, 60, and 100% of the maximum voluntary contraction; MVC). An internal focus of attention reduced the accuracy of force being produced and increased cocontraction of the antagonist muscle. Error on a given trial was positively correlated with the magnitude of cocontraction on that trial. Experiment 2 tested the effects of attention on muscular fatigue at 30, 60 and 100%MVC. An internal focus of attention led to less efficient intermuscular coordination, especially early in the contraction. These results suggest that an internal focus of attention disrupts efficient motor control in force production resulting in increased cocontraction, which potentially explains other neuromechanical findings (e.g. reduced functional variability with an internal focus).     

Not so fast: Rethinking the effects of action video games on attentional capacity

Considerable excitement has been generated by recent studies showing that video gaming alters fundamental aspects of attention. We tested the claim that people who frequently play action video games (video game players (VGPs)) have a greater capacity of attention than those who rarely play video games (non‐video game players (NVGPs)). We first attempted to replicate previous findings by comparing VGPs and NVGPs on a flanker compatibility task (Experiment 1). In contrast with previous studies, VGPs did not demonstrate greater intrusion from distractors, calling into question the reliability of previous findings. In Experiment 2, we manipulated the eccentricity of flankers in an Eriksen flanker task to examine the extent to which VGPs and NVGPs processed irrelevant peripheral stimuli. No attentional differences emerged in the conditions tested, with both groups displaying compatibility effects at all eccentricities. Together these results raise doubts that video game playing increases attentional capacity.