Unfulfilled goals interfere with tasks that require executive functions

Even after one stops actively pursuing a goal, many mental processes remain focused on the goal (e.g., the Zeigarnik effect), potentially occupying limited attentional and working memory resources. Five studies examined whether the processes associated with unfulfilled goals would interfere with tasks that require the executive function, which has a limited focal capacity and can pursue only one goal at a time. In Studies  and , activating a goal nonconsciously and then manipulating unfulfillment caused impairments on later tasks requiring fluid intelligence (solving anagrams; Study 1) and impulse control (dieting; Study 2). Study 3 showed that impairments were specific to executive functioning tasks: an unfulfilled goal impaired performance on logic problems but not on a test of general knowledge (only the former requires executive functions). Study 4 found that the effect was moderated by individual differences; participants who reported a tendency to shift readily amongst their various pursuits showed no task interference. Study 5 found that returning to fulfill a previously frustrated goal eliminated the interference effect. These findings provide converging evidence that unfulfilled goals can interfere with later tasks, insofar as they require executive functions.     

Reversing the Signaled Magnitude Effect in Delayed Matching to Sample: Delay-specific Remembering

Pigeons performed a delayed matching‐to‐sample task in which large or small reinforcers for correct remembering were signaled during the retention interval. Accuracy was low when small reinforcers were signaled, and high when large reinforcers were signaled (the signaled magnitude effect). When the reinforcer‐size cue was switched from small to large partway through the retention interval, accuracy accordingly changed from low to high. The opposite happened when the cue was switched from large to small. This dissociation of forgetting from the passage of time raises the possibility that remembering is delay‐specific. The reversal of the signaled magnitude effect during the retention interval is consistent with an attentional account in which the stimulus control of remembering is influenced by extraneous events.     

Reinforced stimulus preexposure effects as a function of US intensity: Implications for understanding the Hall-Pearce effect

Three conditioned suppression experiments examined the Hall-Pearce (1979) negative transfer effect in rats. Experiment 1 replicated the effect: CS-US_weak pairings retarded subsequent fear conditioning to the CS as a result of CS-US_strong pairings. The size of this retardation was less than that produced by non-reinforced CS presentations (latent inhibition). When the magnitude of the US_weak was reduced in Experiment 2, the Hall-Pearce effect was greater than latent inhibition. Experiment 3 confirmed the findings of the two previous experiments, and demonstrated that magnitude of the Hall-Pearce negative transfer effect is inversely related to the magnitude of the US_weak. From these findings it is suggested that the Hall-Pearce effect consists of a balance between a positive transfer of associative strength, and negative transfer based on CS- and US-preexposure effects.     

两种范式下有意遗忘的实验研究

本文以英语词汇为材料,采用自由回忆和再认测验作为外显记忆测验,词干补笔测验作为内隐记忆测验,探讨小学五年级学生在单字范式与字表范式下的有意遗忘效应及其机制。结果发现:(1)单字范式下,三种测验中都存在有意遗忘效应;而字表范式下,只有词干补笔和自由回忆测验中存在有意遗忘效应;(2)三种测验中,单字范式下记忆项与遗忘项的差异显著高于字表范式下二者的差异。这表明,两种范式下有意遗忘效应产生的机制是不一致的,且相较于字表范式,单字范式下有意遗忘效应更显著。     

Eye movement suppression interferes with construction of object-centered spatial reference frames in working memory

The brain’s frontal eye fields (FEF), responsible for eye movement control, are known to be involved in spatial working memory (WM).In a previous fMRI experiment (Wallentin, Roepstorff & Burgess, Neuropsychologia, 2008) it was found that FEF activation was primarily related to the formation of an object-centered, rather than egocentric, spatial reference frame. In this behavioral experiment we wanted to demonstrate a causal relationship between eye movement control and manipulation of spatial reference frames. Sixty-two participants recalled either spatial (“Was X in front of Y?”) or non-spatial (“Was X darker than Y?”) relations in a previously shown image containing two to four objects, each with an intrinsic orientation and unique luminance. During half of all recall trials a moving visual stimulus was presented, which participants had to ignore, thus suppressing eye movement. Response times were significantly slower for spatial relations with distraction while there was no effect on non-spatial relations. There was no effect on accuracy, i.e. WM maintenance. This is consistent with the hypothesis that in spatial representations the FEFs are involved in WM content manipulation, such as establishing an object-centered spatial frame of reference.     

Use of an ambiguous-sample procedure to establish a cue to forget in pigeons

Pigeons were trained on a variation of the matching-to-sample task in which on double-sample trials two samples, one associated with each of the comparison stimuli, were presented successively. Responding to the comparison associated with the first sample was reinforced on half the double-sample trials, and responding to the comparison associated with the second sample was reinforced on the remaining half. One of two postsample stimuli was presented following the termination of each colored sample. A vertical line was presented after a correct or target sample, and a horizontal line was presented after an incorrect or interfering sample. With extended training, each bird demonstrated above-chance accuracy on double-sample trials, providing prima facie evidence that one or both of the postsample stimuli exerted control over matching behavior. Experiment 2 provided evidence that the horizontal line functioned as a cue to forget the code activated by the preceding sample stimulus. It was concluded that a condition sufficient to establish a postsample stimulus as a cue to forget is that the postsample immediately follow presentation of a sample that, if it were to control test responding, would lead to nonreinforcement.     

Effects of diazepam on schedule-controlled and schedule-induced behavior under signaled and unsignaled shock.

Schedule-controlled lever pressing and schedule-induced licking were studied in rats under a multiple fixed-interval fixed-interval schedule of food reinforcement upon which was superimposed a multiple variable-time variable-time schedule of electric-shock delivery. Shocks were signaled in one component of the multiple schedule and unsignaled in the other. The effects of diazepam upon the suppression of behavior during the signal (conditioned suppression) and during signaled and unsignaled shock (differential suppression) were studied under several shock intensities (Experiment 1) and at increased body weight (Experiment 2). In each study, diazepam led to dose-dependent increases in the rate of pressing and licking during signaled and unsignaled shock, but had little effect on conditioned suppression. the rate-enhancing effects of diazepam depended upon the intensity of shock, nature of the response, and whether or not shocks were signaled. The data was discussed in terms of (1) implications for understanding the effects of signaled and unsignaled shock on behavior, (2) the effects of diazepam on behavior suppressed by response-independent shock, and (3) comparison between operant and schedule-induced behavior.     

THE EXPERIMENTAL MODIFICATION OF SONOROUS BREATHING

Loud snoring is a noxious habit and potential personal health risk. We are reporting the first experimental study of simple behavioral techniques for the modification of chronic snoring. Twenty-four volunteers participated in a repeated measures, randomized group design over 2 weeks of intervention and one-month follow-up. Treatment groups included a contingent-awakening and breathing retraining (self-control) condition. Both treatment groups were compared to a no-treatment control. Despite considerable intrasubject variability and the lack of an adequate attention-placebo control group, objective assessment indicated a substantial reduction in snoring amplitude and frequency in both treatment groups. Follow-up assessments further demonstrated maintenance of change. This study has implications for modification of sleep habit disorders and learning without awareness.     

An investigation of the differential-outcomes effect within sessions

The differential-outcomes effect is manifest as more accurate performance of a delayed conditional discrimination when alternative choice responses are followed by different reinforcers than when they are followed by the same reinforcer. In Experiment 1, a differential-outcomes effect was demonstrated within sessions by signaling the duration of food access for correct responses with stimuli appearing in conjunction with the sample stimuli. The delayed matching-to-sample performance of 5 pigeons was more accurate when green choice responses (matching a green sample) were followed by 3.5-s food access and red choice responses (matching a red sample) were followed by 0.5-s food access (different-outcome trials) than when the correct choice responses were both followed by 1.5-s reinforcers (same-outcome trials). In Experiment 2, the acquisition of this differential-outcomes effect was characterized by a progressive decrease in rate of forgetting on different-outcome trials and no change in rate of forgetting on same-outcome trials. In addition, accuracy at the shortest delay intervals for both different-outcome and same-outcome trials increased over acquisition, but to a greater extent for different-outcome trials. These data suggest that both memorial and attentional (time-dependent and time-independent) factors contribute to the differential-outcomes effect.