Arousal (but not valence) amplifies the impact of salience

Previous findings indicate that negative arousal enhances bottom-up attention biases favouring perceptual salient stimuli over less salient stimuli. The current study tests whether those effects were driven by emotional arousal or by negative valence by comparing how well participants could identify visually presented letters after hearing either a negative arousing, positive arousing or neutral sound. On each trial, some letters were presented in a high contrast font and some in a low contrast font, creating a set of targets that differed in perceptual salience. Sounds rated as more emotionally arousing led to more identification of highly salient letters but not of less salient letters, whereas sounds’ valence ratings did not impact salience biases. Thus, arousal, rather than valence, is a key factor enhancing visual processing of perceptually salient targets.     

Phenylpropanolamine inhibits feeding, but not drinking, induced by hypothalamic stimulation.

In rats bearing lateral hypothalamic electrodes that elicited both feeding and drinking, intraperitoneal injection of the appetite suppressant drug phenylpropanolamine (Propadrine) inhibited only feeding. This occurred whether feeding and drinking were tested simultaneously or separately. Selective inhibition of lateral hypothalamic feeding also followed injection of this drug through lateral, but not medial, hypothalamic electrode cannulas. We conclude that hypothalamically induced feeding is under some of the same pharmacological controls as spontaneous feeding, that this control may be exerted, in part, in or near the lateral hypothalamus, and that the neural systems which induce feeding and drinking during hypothalamic stimulation can be pharmacologically separated.     

Children (but not adults) can inhibit false memories

The role of inhibition in children's (5-, 7-, and 11-year-olds') false memory illusions in the Deese-Roediger-McDermott (DRM) paradigm was examined using a list-wise directed-forgetting procedure. Children studied either a single DRM list (control) or two DRM lists in succession with a directed-remembering instruction or a directed-forgetting instruction between list presentations. The findings indicated that, like adults, children effectively suppressed the output of true memories when given a directed-forgetting instruction. Unlike adults, whose false memories are not attenuated in directed-forgetting conditions, children suppressed false memories at recall in the directed-forgetting condition. Because recognition data indicated that the children did generate false memories regardless of instruction, it appears that although adults' false memories are generated automatically and do not become part of their conscious experience, children's false memories are produced with greater effort and conscious processing, and as a result are easier to suppress at output.     

Many questions Begs the Question (but questions do not Beg the Question)

The fallacy of many questions or the complex question, popularized by the sophism ‘Have you stopped beating your spouse?’ (when a yes-or-no answer is required), is similar to the fallacy of begging the question orpetitio principii. Douglas N. Walton inBegging the Question has recently argued that the two forms are alike in trying unfairly to elicit an admission from a dialectical opponent without meeting burden of proof, but distinct because of the circularity of question-begging argument and noncircularity of many questions. I offer a reconstruction of the many questions fallacy according to which it is just as circular as begging the question, concluding that many questions begs the question. The same analysis contradicts Walton's claim that questions can beg the question, drawing a distinction between questions as the instruments of question-begging, and as vehicles for categorical noninterrogative presuppositions that beg the question.     

In Defense of Penalizing (but not Punishing) Civil Disobedience

While many contemporary political philosophers agree that citizens of a legitimate state enjoy a moral right to civil disobedience, they differ over both the grounds of that right and its content. This essay defends the view that the moral right to civil disobedience derives from (or is a facet of) a general right to political participation, and the characterization of that right as precluding the state from punishing, but not from penalizing, those who exercise it. The argument proceeds by way of rebuttals to criticisms of both claims recently advanced by Kimberley Brownlee. While in some cases those criticisms fail on their merits, in other cases the responses offered here reveal that the dispute over the ground and content of a moral right to civil disobedience reflects deeper disagreements regarding two foundational issues: first, whether moral rights are best conceived of as defeasible evaluative principles or conclusive normative ones, and second, whether principles of justice should be theorized on the basis of full or partial compliance.     

Large-billed crows (Corvus macrorhynchos) have retrospective but not prospective metamemory

Evidence of metamemory, the ability to monitor one’s own memory, has been obtained in some primates, but it appears to be weaker in other species. In this study, we examined whether crows flexibly modulate their behavior by monitoring the strength of memory trace in a delayed matching-to-sample task using two paradigms. First, crows performing a memory test were given an escape option to decline taking the test (prospective metamemory). Second, crows were given the escape option as a “not confident” report after completing the test (retrospective metamemory). Accurate memory performance yielded a reward with a higher probability, whereas inaccurate memory performance resulted in no such recompense. The escape option yielded a reward with a lower probability. In the prospective metamemory test, crows escaped the memory test more frequently with longer delay intervals than they did with shorter delay intervals but no more frequently in the sample-omission than the sample-present trials, indicating that the crows decided to take the test or decline it by using the delay interval as a cue. In contrast, in the retrospective metamemory test, the crows escaped the memory test more frequently when their memory-test response was incorrect than correct and more frequently in the sample-omission than the sample-present trials, indicating that the crows recognized confidence regarding their choice in the memory test and utilized the escape option to maximize reward probability. Although these results suggest that crows retrospectively monitor the strength of memory trace, their prospective metamemory ability has not yet been confirmed in the present paradigm.     

Perceived lightness, but not brightness, of achromatic surfaces depends on perceived depth information

Three experiments were conducted in an attempt to replicate and clarify Gilchrist's (1977, 1980) experiments on the effects of depth information on judgments of achromatic surface color. Gilchrist found that coplanarity, and not retinal adjacency, was the dominant factor in determining achromatic color matches. Because such matches can be made on the basis of either brightness or lightness, we obtained judgments of both qualities. Stereopsis was added to enhance the perceived depth effect of Gilchrist's display, which was otherwise simulated closely on a high-resolution CRT. The results for lightness followed the same pattern as those of Gilchrist, but were smaller in magnitude. This discrepancy may reflect reduced extraneous lighting effects in our displays. Our results therefore agree with related studies in suggesting that lightness matches are based on relationships among coplanar surfaces. Brightness matches, however, were not influenced by perceived depth.     

What time travelers cannot not do (but are responsible for anyway)

The Principle of Alternative Possibilities is the intuitive idea that someone is morally responsible for an action only if she could have done otherwise. Harry Frankfurt has famously presented putative counterexamples to this intuitive principle. In this paper, I formulate a simple version of the Principle of Alternative Possibilities that invokes a course-grained notion of actions. After warming up with a Frankfurt-Style Counterexample to this principle, I introduce a new kind of counterexample based on the possibility of time travel. At the end of the paper, I formulate a more sophisticated version of the Principle of Alternative Possibilities that invokes a certain fine grained notion of actions. I then explain how this new kind of counterexample can be augmented to show that even the more sophisticated principle is false.     

Measuring biting behavior induced by acute stress in the rat

Previous reports have indicated that biting behavior is enhanced in rats that are subject to acute stress. Several methods have been proposed for studying this phenomenon, one of which is the electromyography (EMG) of the jaw muscles. In this study, we compared total EMG activity with the EMG activity related to biting behavior, as determined by video monitoring, before and after restraint stress. Wistar albino rats (150 g) were subject to surgery for electrode placement 48 h before measurements. The EMG activity of the masseter muscle on one side was recorded for 10 min before and immediately after 30 min of restraint stress. Restraint stress increased jaw muscle EMG activity, although some of the activity was related to behaviors other than biting. Recording the EMG activity of jaw muscles is useful for measuring the stress response in rats, but careful video monitoring is needed if biting behavior is to be studied in particular.     

Basolateral amygdala inactivation impairs learned (but not innate) fear response in rats

Numerous studies have suggested that the amygdala is involved in the formation of aversive memories, but the possibility that this structure is merely related to any kind of fear sensation or response could not be ruled out in previous studies. The present study investigated the effects of bilateral inactivation of the amygdaloid complex in rats tested in the plus-maze discriminative avoidance task. This task concomitantly evaluates aversive memory (by discrimination of the two enclosed arms) and innate fear (by open-arm exploration). Wistar rats (3-5 months-old) were implanted with bilateral guide cannulae into basolateral amygdala. After surgery, all subjects were given 1 week to recover before behavioral experiments. Afterwards, in experiment 1, 15 min prior to training, 0.5 μl of saline or muscimol (1 mg/ml) was infused in each side via microinjection needles. In experiment 2 the animals received injections immediately after the training session and in experiment 3 rats were injected prior to testing session (24 h after training). The main results showed that (1) pre-training muscimol prevented memory retention (evaluated by aversive arm exploration in the test session), but did not alter innate fear (evaluated by percent time in open arms); (2) post-training muscimol impaired consolidation, inducing increased percent in aversive arm exploration in the test session and (3) pre-testing muscimol did not affect retrieval (evaluated by aversive enclosed arm exploration in the test session). The results suggest that amygdala inactivation specifically modulated the learning of the aversive task, excluding a possible secondary effect of amygdala inactivation on general fear responses. Additionally, our data corroborate the hypothesis that basolateral amygdala is not the specific site of storage of aversive memories, since retention of the previously learned task was not affected by pre-testing inactivation.     

Rapid naming is affected by association but not by syntax

Three experiments are reported that focused on the grammatical and associative relationship between a single-word context and a to-be-named target in the Serbo-Croatian language. Unlike in studies using the English language, word class need not be violated in order to obtain grammatical incongruency: all word pairs, therefore, can be semantically plausible. Experiment 1 contrasted naming with lexical decision using associative and grammatical priming, a replication of Seidenberg, Waters, Sanders, and Langer’s (1984) study. With associative priming, both lexical decision and naming were facilitated significantly, but with grammatical priming, only lexical decision was affected significantly. Heeding observations of West and Stanovich (1986), in Experiment 2 we used stimuli known to produce a robust grammatical congruency effect on lexical decision (130 msec) and a procedure designed to slow naming latencies. Again, no grammatical congruency effect for naming was obtained. Finally, because Experiment 1, which used a row of Xs as the neutral context, showed an associative priming effect on naming pseudowords, Experiment 3 used a neutral context that was linguistic. An associative priming effect was found for words but not for pseudowords. Results were discussed in terms of pre- and postlexical loci of contextual effects.     

Fatty acid amide hydrolase (FAAH) knockout mice exhibit enhanced acquisition of an aversive, but not of an appetitive, Barnes maze task

It is well established that genetic deletion or pharmacological inhibition of the CB₁ receptor disrupts extinction learning in aversive conditioning tasks, but not in appetitive tasks. Consistent with these findings is that genetic deletion or pharmacological inhibition of fatty acid amide hydrolase (FAAH), the primary catabolic enzyme of the endogenous cannabinoid anandamide (AEA), accelerates acquisition as well as extinction in aversive conditioning tasks. However, it is unknown whether FAAH blockade will affect acquisition in an appetitive conditioning task. Therefore, in the present study, we assessed FAAH (−/−) and (+/+) mice in appetitive and aversive Barnes maze conditioning procedures. Here we report that FAAH (−/−) mice displayed accelerated acquisition rates in an aversively-motivated, but not in the appetitively-motivated, Barnes maze task. The CB₁ receptor antagonist, rimonabant attenuated enhanced acquisition in the aversive procedure, consistent with the idea that elevated AEA levels mediate this apparent nootropic effect. These findings support the hypothesis that stimulation of the endocannabinoid system enhances learned behavior in aversive, but not appetitive, conditioning paradigms.     

Interdependent self‐construal moderates coping with (but not the initial pain of) ostracism

Ostracism – being excluded and ignored – can cause psychological distress. There has been little research examining how a person's concept of self might influence the effects of ostracism. In the current study, we sought to examine the effect of self‐construal on the distress created by ostracism. Specifically, we assessed the potential moderating effects of self‐construal on both the initial distress of ostracism and the coping process. Participants, recruited in China, completed a self‐construal measure and were either included or ostracized in an online ball‐tossing game. They then reported need‐satisfaction both immediately following the game and after a filler task. Interdependent self‐construal facilitated participants' recovery from some of the negative effects of ostracism, but did not have an impact on the initial pain.     

Lesion of the ventral periaqueductal gray reduces conditioned fear but does not change freezing induced by stimulation of the dorsal periaqueductal gray

Previously-reported evidence showed that freezing to a context previously associated with footshock is impaired by lesion of the ventral periaqueductal gray (vPAG). It has also been shown that stepwise increase in the intensity of the electrical stimulation of the dorsal periaqueductal gray (dPAG) produces alertness, then freezing, and finally escape. These aversive responses are mimicked by microinjections of GABA receptor antagonists, such as bicuculline, or blockers of the glutamic acid decarboxylase (GAD), such as semicarbazide, into the dPAG. In this work, we examined whether the expression of these defensive responses could be the result of activation of ventral portion of the periaqueductal gray. Sham- or vPAG electrolytic–lesioned rats were implanted with an electrode in the dPAG for the determination of the thresholds of freezing and escape responses. The vPAG electrolytic lesions were behaviorally verified through a context-conditioned fear paradigm. Results indicated that lesion of the vPAG disrupted conditioned freezing response to contextual cues associated with footshocks but did not change the dPAG electrical stimulation for freezing and escape responses. In a second experiment, lesion of the vPAG also did not change the amount of freezing and escape behavior produced by microinjections of semicarbazide into the dPAG. These findings indicate that freezing and escape defensive responses induced by dPAG stimulation do not depend on the integrity of the vPAG. A discussion on different neural circuitries that might underlie different inhibitory and active defensive behavioral patterns that animals display during threatening situations is presented.