Unintentional preparation of motor impulses after incidental perception of need-rewarding objects

Using a new method, we examined whether incidental perception of need-rewarding (positive) objects unintentionally prepares motor action. Participants who varied in their level of need for water were presented with glasses of water (and control objects) that were accompanied by go and no-go cues that required a response (key-press) or withholding a response. Importantly, if need-rewarding objects unintentionally prepare action, presentation of no-go cues should lead to motor inhibition of these prepared motor impulses. Consistent with this hypothesis, results showed that participants relatively high in need for water (and hence, who perceive water as a rewarding, positive object) were slower to react to a successive action probe after withholding a response during perception of water than during perception of the control object, suggesting motor inhibition of unintentionally prepared motor impulses. We propose that incidental perception of need-rewarding objects unintentionally potentiates preparation of motor action to these objects.     

Differences in psychosocial factors and fat consumption between stages of change for fat reduction

Abstract

Differences in fat consumption and psychosocial factors between subjects in different trans-theoretical stages of change for fat reduction were studied. Data on fat consumption, self-rated fat intake, attitudes, social support and self-efficacy were collected among a sample of 507 adults. Analysis of variance with Scheffe's multiple-comparison test was used to study differences in these factors between stages of change. Attitudes and social support were most positive among subjects in preparation and action. Self-efficacy expectations were lowest among subjects in contemplation and preparation. Fat consumption was highest among precontemplators hut no substantial differences between other stages were found. It is concluded that subjects in different stages of change differ in psychosocial factors that are regarded as important determinants of behavioral change. Based on these differences it is recommended to develop stage-tailored nutrition education. A majority of subjects in maintenance consumed more fat than is recommended. Therefore, it is suggested that the usually applied staging algorithms might need adjustment for a valid application in nutrition research.     

Cueing task goals and earning money: Relatively high monetary rewards reduce failures to act on goals in a Stroop task

We examined the role of monetary rewards in failures to act on goals in a Stroop task. Based on recent developments in theorizing on the interplay between rewards and cognitive control, we hypothesized that relatively high monetary rewards enhance the focus and stability of a cued task goal compared to low monetary rewards, and hence cause a reduction in failures to act on current task goals under circumstances that warrant top–down goal implementation. To test this, participants received a modified version of the Stroop task, in which they were either briefly cued with the goal of naming the color or meaning of targets on a trial-by-trial basis. After goal cuing, but before presenting the target, either a low or high reward cue was presented. Results showed that higher rewards produced a general speed-up. More importantly, Stroop interference on error rates was lower in the high reward condition compared to the low reward condition, revealing that the rewards enhanced focus and stability of the cued goal. These results provide support for theorizing that reward processing modulates utility assessment of current goals by affecting attention to facilitate goal-directed behavior.     

Unintentional preparation of motor impulses after incidental perception of need-rewarding objects

Using a new method, we examined whether incidental perception of need-rewarding (positive) objects unintentionally prepares motor action. Participants who varied in their level of need for water were presented with glasses of water (and control objects) that were accompanied by go and no-go cues that required a response (key-press) or withholding a response. Importantly, if need-rewarding objects unintentionally prepare action, presentation of no-go cues should lead to motor inhibition of these prepared motor impulses. Consistent with this hypothesis, results showed that participants relatively high in need for water (and hence, who perceive water as a rewarding, positive object) were slower to react to a successive action probe after withholding a response during perception of water than during perception of the control object, suggesting motor inhibition of unintentionally prepared motor impulses. We propose that incidental perception of need-rewarding objects unintentionally potentiates preparation of motor action to these objects.     

Computing the meanings of words in reading: cooperative division of labor between visual and phonological processes

Are words read visually (by means of a direct mapping from orthography to semantics) or phonologically (by mapping from orthography to phonology to semantics)? The authors addressed this long-standing debate by examining how a large-scale computational model based on connectionist principles would solve the problem and comparing the model's performance to people's. In contrast to previous models, the present model uses an architecture in which meanings are jointly determined by the 2 components, with the division of labor between them affected by the nature of the mappings between codes. The model is consistent with a variety of behavioral phenomena, including the results of studies of homophones and pseudohomophones thought to support other theories, and illustrates how efficient processing can be achieved using multiple simultaneous constraints.     

Corticosterone time-dependently modulates beta-adrenergic effects on long-term potentiation in the hippocampal dentate gyrus

Previous experiments in the hippocampal CA1 area have shown that corticosterone can facilitate long-term potentiation (LTP) in a rapid non-genomic fashion, while the same hormone suppresses LTP that is induced several hours after hormone application. Here, we elaborated on this finding by examining whether corticosterone exerts opposite effects on LTP depending on the timing of hormone application in the dentate gyrus as well. Moreover, we tested rapid and delayed actions by corticosterone on β-adrenergic-dependent changes in LTP. Unlike the CA1 region, our in vitro field potential recordings show that rapid effects of corticosterone do not influence LTP induced by mild tetanization in the hippocampal dentate gyrus, unless GABA_A receptors are blocked. In contrast, the β-adrenergic agonist isoproterenol does initiate a slow-onset, limited amount of potentiation. When corticosterone was applied concurrently with isoproterenol, a further enhancement of synaptic strength was identified, especially during the early stage of potentiation. Yet, treatment with corticosterone several hours in advance of isoproterenol fully prevented any effect of isoproterenol on LTP. This emphasizes that corticosterone can regulate β-adrenergic modulation of synaptic plasticity in opposite directions, depending on the timing of hormone application.     

Putting behavior on hold decreases reward value of need-instrumental objects outside of awareness

We examined whether cues that put impulsive behavior towards rewarding objects on hold reduces the value of the rewarding objects outside of conscious awareness. We manipulated the reward value of water by making participants thirsty, or not. Next, a bottle of water was subliminally presented in a go/no-go task, and paired with either go cues or no-go cues (putting behavior on hold). Subsequently, as a measure of reward value of water, participants estimated the size of water objects. Results showed that repeatedly withholding behavior towards water reduced the perceived size of water objects, but only when participants were made thirsty. These results suggest that withholding impulsive behavior towards objects that serve basic needs nonconsciously reduces reward value of these objects. Implications for nonconscious behavior regulation are briefly discussed.