Resource depletion promotes automatic processing: implications for distribution of practice

Recent models of cognition include two processing systems: an automatic system that relies on associative learning, intuition, and heuristics, and a controlled system that relies on deliberate consideration. Automatic processing requires fewer resources and is more likely when resources are depleted. This study showed that prolonged practice on a resource-depleting mental arithmetic task promoted automatic processing on a subsequent problem-solving task, as evidenced by faster responding and more errors. Distribution of practice effects (0, 60, 120, or 180 sec. between problems) on rigidity also disappeared when groups had equal time on resource-depleting tasks. These results suggest that distribution of practice effects is reducible to resource availability. The discussion includes implications for interpreting discrepancies in the traditional distribution of practice effect.     

Perceptual learning with a sodium depletion procedure

Rats in a state of salt need prefer a flavor that has previously been paired with saline (Experiment 1). In Experiments 2 and 3, rats exposed to 2 saline concentrations, presented either concurrently or on separate trials, and each paired with a different flavor, showed a preference for the flavor that had been associated with the stronger saline. This effect was substantial, however, only in those rats that had experienced the concurrent exposure schedule. This effect cannot be attributed to a difference in the strength of within-compound associations produced by the 2 preexposure schedules (Experiment 4). It is suggested that concurrent preexposure can engage a learning process that enhances the discriminability of the preexposed stimuli.     

A detector of sonic and ultrasonic vocalizations with frequency readout

An electronic apparatus to detect vocalizations between 4 and 50 kHz and to provide frequency readout is described. A frequency-to-voltage converter changes vocalizations to their analog. A peak-and-hold circuit retains and gates the maximal value of this analog voltage while it is accessed by a chart recorder or computer. Provision is made to lock out noise by inhibiting the device’s response to all signals lower than those associated with a selectable cutoff frequency. In preliminary tests of the apparatus, vocal signals of two rats in a common cage were recorded while the animals were subjected to a brief, intermittent bout of faradic shock to the feet. All recorded vocalizations occurred at frequencies below 26 kHz.     

Inhibitory sensory preconditioning detected with a sodium depletion procedure

In each of two experiments, two groups of rats were exposed to three flavoured solutions: A (citric acid), B (salt), and AX (a compound of citric acid and saccharin). Both experiments used a between-subjects design in which a paired group received presentations of A followed by B, alternating with presentations of AX (i.e., A → B/AX), and an unpaired group received alternating presentations of A, B, and AX (i.e., A/B/AX). This arrangement was expected to establish X as an inhibitor of B in group paired but not in group unpaired. In Experiment 1, after preexposure all subjects received a single presentation of an XB compound, then experienced sodium depletion, and were tested for their consumption of X, which was greater in group unpaired than in group paired. In Experiment 2, after preexposure, all subjects received four presentations of a new flavour, C, in compound with B and subsequently, under sodium depletion, were tested for consumption of XC. Intake of the XC compound was less in group paired than in group unpaired. These results suggest that, in group paired, X acquired an inhibitory relationship with B both retarding the acquisition of an excitatory association with B (retardation test, Experiment 1) and reducing the response to a new stimulus, C, strongly associated to B (summation test, Experiment 2). These results provide direct evidence of inhibition between two neutral stimuli and, therefore, of inhibitory sensory preconditioning.     

Inhibitory sensory preconditioning detected with a sodium depletion procedure

In each of two experiments, two groups of rats were exposed to three flavoured solutions: A (citric acid), B (salt), and AX (a compound of citric acid and saccharin). Both experiments used a between-subjects design in which a paired group received presentations of A followed by B, alternating with presentations of AX (i.e., A → B/AX), and an unpaired group received alternating presentations of A, B, and AX (i.e., A/B/AX). This arrangement was expected to establish X as an inhibitor of B in group paired but not in group unpaired. In Experiment 1, after preexposure all subjects received a single presentation of an XB compound, then experienced sodium depletion, and were tested for their consumption of X, which was greater in group unpaired than in group paired. In Experiment 2, after preexposure, all subjects received four presentations of a new flavour, C, in compound with B and subsequently, under sodium depletion, were tested for consumption of XC. Intake of the XC compound was less in group paired than in group unpaired. These results suggest that, in group paired, X acquired an inhibitory relationship with B both retarding the acquisition of an excitatory association with B (retardation test, Experiment 1) and reducing the response to a new stimulus, C, strongly associated to B (summation test, Experiment 2). These results provide direct evidence of inhibition between two neutral stimuli and, therefore, of inhibitory sensory preconditioning.     

On the malleability of automatic attitudes: combating automatic prejudice with images of admired and disliked individuals.

Two experiments examined whether exposure to pictures of admired and disliked exemplars can reduce automatic preference for White over Black Americans and younger over older people. In Experiment 1, participants were exposed to either admired Black and disliked White individuals, disliked Black and admired White individuals, or nonracial exemplars. Immediately after exemplar exposure and 24 hr later, they completed an Implicit Association Test that assessed automatic racial attitudes and 2 explicit attitude measures. Results revealed that exposure to admired Black and disliked White exemplars significantly weakened automatic pro-White attitudes for 24 hr beyond the treatment but did not affect explicit racial attitudes. Experiment 2 provided a replication using automatic age-related attitudes. Together, these studies provide a strategy that attempts to change the social context and, through it, to reduce automatic prejudice and preference.     

Security and potential level preferences with thresholds

The security level models of Gilboa [1988. A combination of expected utility and maxmin decision criteria. Journal of Mathematical Psychology, 32, 405-420] and of Jaffray [1988. Choice under risk and the security factor: An axiomatic model. Theory and Decision, 24, 169-200] as well as the security and potential level model of Cohen [1992. Security level, potential level, expected utility: A three-criteria decision model under risk. Theory and Decision, 33, 101-104] and Essid [1997. Choice under risk with certainty and potential effects: A general axiomatic model. Mathematical Social Sciences, 34, 223-247] successfully accommodate classical Allais paradoxes while they offer an interesting explanation for their occurrence. However, experimental data suggest a systematic violation of these models when lotteries with low probabilities of bad or good outcomes are involved. In our opinion, one promising candidate for the explanation of these violations is the assumption of thresholds in the perception of security and potential levels. The present paper develops an axiomatic model that allows for such thresholds, so that the derived representation of preferences can accommodate the observed violations of the original security and potential level models.     

Impulsive choice and altruistic punishment are correlated and increase in tandem with serotonin depletion

Human cooperation may partly depend on the presence of individuals willing to incur personal costs to punish noncooperators. The psychological factors that motivate such 'altruistic punishment' are not fully understood; some have argued that altruistic punishment is a deliberate act of norm enforcement that requires self-control, while others claim that it is an impulsive act driven primarily by emotion. In the current study, we addressed this question by examining the relationship between impulsive choice and altruistic punishment in the ultimatum game. As the neurotransmitter serotonin has been implicated in both impulsive choice and altruistic punishment, we investigated the effects of manipulating serotonin on both measures. Across individuals, impulsive choice and altruistic punishment were correlated and increased following serotonin depletion. These findings imply that altruistic punishment reflects the absence rather than the presence of self control, and suggest that impulsive choice and altruistic punishment share common neural mechanisms.     

An increase in strength of tilt aftereffect associated with tryptophan depletion

The effects of a tryptophan-free amino acid mixture on tilt aftereffect, movement aftereffect, and the Mueller-Lyer illusion were studied. 12 male subjects ingested either a balanced amino acid mixture or a tryptophan-free mixture which causes a marked depletion of brain tryptophan and serotonin. The tryptophan-free mixture significantly increased the strength of tilt aftereffect but had no effect on movement aftereffect or the Mueller-Lyer illusion. These results were discussed with reference to the pharmacological activity of serotonin and its influence on the strength of lateral inhibition in mammalian brains.     

An integrated circuit photocell detector and sequencer

A simple, inexpensive, and reliable apparatus for photocell detection and amplification is described. The sensitivity, voltage and current amplification, and speed of this apparatus, make it well suited to application in latency measurement in animal mazes. The apparatus can be used in any sort of application where a resistive type of transducer is needed to trigger some other event at higher voltage and current levels than can be done directly by the transducer alone.     

Affect and automatic mood maintenance

The hedonic contingency model (HCM; Wegener & Petty, 1994) states that individuals have learned to seek out positive activities while in a happy mood in order to maintain or elevate that mood. We argue that this tendency may become overlearned and, thus, automated. More specifically, the experience of a happy mood was predicted to automatically activate the mood-maintenance tendency proposed by the HCM. Participants induced into happy, sad, or neutral moods ranked their preferences for future activities that were nonconsciously associated with either a positive or negative valence. Supporting the notion of automatic mood maintenance, happy participants appeared to evaluate the affective qualities of the future activities and base their preferences on this evaluation without realizing that they were doing so. Theoretical implications of this finding are discussed.     

Alexithymia and automatic affective processing

According to recent theories of emotion evaluative information is activated automatically in the associative network on the observation of a stimulus. This study investigates the relationship between alexithymic personality dimensions and automatic affective facilitation effects. The 20-Item Toronto Alexithymia Scale (TAS-20) was administered to 32 subjects along with two sequential word–word priming tasks (a pronunciation and an evaluation task). The TAS-20 scale ‘Difficulties Describing Feelings’ showed a correlation with affective facilitation based on negative stimuli, whereas the scale ‘Externally Oriented Thinking’ as well as the TAS-20 sum score correlated with affective facilitation based on positive stimuli. Thus, some evidence was found that individuals with difficulties verbalizing their emotions are especially sensitive to the negative valence of stimuli at a pre-attentive level. It is argued that the scale ‘Difficulties Describing Feelings’ might assess aspects of social anxiety or shame. Individuals who report a pragmatic and externally oriented cognitive style seem to be characterized by a heightened perceptual sensitivity for positive information. Methodological problems in measuring affective priming effects are discussed. © 1998 John Wiley & Sons, Ltd.     

Evidence for conditional sex differences in emotional but not in sexual jealousy at the automatic level of cognitive processing

The two evolutionary psychological hypotheses that men react more jealous than women to sexual infidelity and women react more jealous than men to emotional infidelity are currently controversial because of apparently inconsistent results. We suggest that these inconsistencies can be resolved when the two hypotheses are evaluated separately and when the underlying cognitive processes are considered. We studied jealousy with forced‐choice decisions and emotion ratings in a general population sample of 284 adults aged 20–30 years using six infidelity dilemmas and recordings of reaction times. The sex difference for emotional jealousy existed for decisions under cognitive constraint, was also evident in the decision speed, increased for faster decisions, and was stronger for participants with lower education. No evidence for a sex difference in sexual jealousy was found. Our results support the view of a specific female sensitivity to emotional infidelity that canalizes the development of an adaptive sex difference in emotional jealousy conditional to the sociocultural environment. Copyright © 2007 John Wiley & Sons, Ltd.     

The relation between fluid intelligence and self-regulatory depletion

Self-regulation depends on a limited resource that can be depleted temporarily, but little is known about how this resource relates to individual differences in cognitive ability. We investigated whether self-regulatory depletion would vary with individual differences in fluid intelligence (gF), a stable index of cognitive ability with ties to executive function. Participants performed an emotion regulation task varying in self-regulatory demand, followed by the Multi-Source Interference Task to assess depletion. On a separate day, participants completed Raven's Advanced Progressive Matrices to assess gF. Emotion suppression led to impairment on the interference task, indicating self-regulatory depletion. Critically, higher gF was associated with greater depletion. Controlling for variables reflecting susceptibility to task demands and trait motivation did not influence this effect. The results have implications for theories of the relation between self-regulatory and cognitive abilities, and the mechanisms supporting the control of behaviour.     

Intact risk-based decision making in rats with prefrontal or accumbens dopamine depletion

The medial prefrontal cortex (mPFC) and the core region of the nucleus accumbens (AcbC) are key regions of a neural system that subserves risk-based decision making. Here, we examined whether dopamine (DA) signals conveyed to the mPFC and AcbC are critical for risk-based decision making. Rats with 6-hydroxydopamine or vehicle infusions into the mPFC or AcbC were examined in an instrumental task demanding probabilistic choice. In each session, probabilities of reward delivery after pressing one of two available levers were signaled in advance in forced trials followed by choice trials that assessed the animal??s preference. The probabilities of reward delivery associated with the large/risky lever declined systematically across four consecutive blocks but were kept constant within four subsequent daily sessions of a particular block. Thus, in a given session, rats need to assess the current value associated with the large/risky versus small/certain lever and adapt their lever preference accordingly. Results demonstrate that the assessment of within-session reward probabilities and probability discounting across blocks were not altered in rats with mPFC and AcbC DA depletions, relative to sham controls. These findings suggest that the capacity to evaluate the magnitude and likelihood of rewards associated with alternative courses of action seems not to rely on intact DA transmission in the mPFC or AcbC.     

Computer-based automatic finger- and speech-tracking system

This article presents the first technology ever for online registration and interactive and automatic analysis of finger movements during tactile reading (Braille and tactile pictures). Interactive software has been developed for registration (with two cameras and a microphone), MPEG-2 video compression and storage on disk or DVD as well as an interactive analysis program to aid human analysis. An automatic finger-tracking system has been implemented which also semiautomatically tracks the reading aloud speech on the syllable level. This set of tools opens the way for large scale studies of blind people reading Braille or tactile images. It has been tested in a pilot project involving congenitally blind subjects reading texts and pictures.     

Offline and online automatic number comparison

This paper focuses on automatic number processing as instantiated in the size congruity effect. It was recently argued that long-term "associations between individual digits and the attributes 'small' and 'large' create the size congruity effect" (Choplin and Logan 2003, abstract, p. 17). Moreover, these authors proposed the additional assumption that the relevant connections are acquired over a lifetime of experience with numbers. We show that at least one of these assumptions is not true: either the size congruity effect derives from an (online) comparison effect between two numbers at the time of stimulus presentation (violating the first assumption) or the relevant connections flexibly change (offline) between trials during the course of one experimental session (violating the second assumption).