Brightness of paired photic pulses with pulse duration and separation varied

The brightness of pairs of photic pulses, differing in pulse duration and pulse separation. was measured. The data were in general agreement with the neurophysiological model of Bishop and Clare. Pulse duration appeared to have little systematic influence on the shape of the curves. Time between onset of the first and second pulse appeared to be a prime factor determining the receptivity of the cortex to the second pulse. The two pulses were seen as single below about .03 sec separation. The second pulse was always judged brighter than the first.     

Behavioral momentum theory fails to account for the effects of reinforcement rate on resurgence

The behavioral‐momentum model of resurgence predicts reinforcer rates within a resurgence preparation should have three effects on target behavior. First, higher reinforcer rates in baseline (Phase 1) produce more persistent target behavior during extinction plus alternative reinforcement. Second, higher rate alternative reinforcement during Phase 2 generates greater disruption of target responding during extinction. Finally, higher rates of either reinforcement source should produce greater responding when alternative reinforcement is suspended in Phase 3. Recent empirical reports have produced mixed results in terms of these predictions. Thus, the present experiment further examined reinforcer‐rate effects on persistence and resurgence. Rats pressed target levers for high‐rate or low‐rate variable‐interval food during Phase 1. In Phase 2, target‐lever pressing was extinguished, an alternative nose‐poke became available, and nose‐poking produced either high‐rate variable‐interval, low‐rate variable‐interval, or no (an extinction control) alternative reinforcement. Alternative reinforcement was suspended in Phase 3. For groups that received no alternative reinforcement, target‐lever pressing was less persistent following high‐rate than low‐rate Phase‐1 reinforcement. Target behavior was more persistent with low‐rate alternative reinforcement than with high‐rate alternative reinforcement or extinction alone. Finally, no differences in Phase‐3 responding were observed for groups that received either high‐rate or low‐rate alternative reinforcement, and resurgence occurred only following high‐rate alternative reinforcement. These findings are inconsistent with the momentum‐based model of resurgence. We conclude this model mischaracterizes the effects of reinforcer rates on persistence and resurgence of operant behavior.     

Eyewitness memory: The impact of a negative mood during encoding and/or retrieval upon recall of a non-emotive event

The police often appeal for eyewitnesses to events that were unlikely to have been emotive when observed. An eyewitness, however, may be in a negative mood whilst encoding or retrieving such events as mood can be influenced by a range of personal, social, and environmental factors. For example, bad weather can induce a negative mood. This experiment compared the impact of negative and neutral moods during encoding and/or retrieval upon eyewitness recall of a non-emotive event. A negative mood during encoding had no impact upon the number of correct details recalled (provided participants were in a neutral mood at retrieval) but a negative mood during retrieval impaired the number of correct details recalled (provided participants were in a neutral mood at encoding). A negative mood at both time points enhanced the number of correct details recalled, demonstrating a mood-dependent memory enhancement. The forensic implications of these findings are discussed.     

'I'm Just Saying . . .': Discourse Markers of Standpoint Continuity

Examining discourse markers (Schiffrin, 1987) in two transcribed discussions of controversial issues in an undergraduate 'critical thinking' class, we note frequent uses of 'I'm just saying' and related metadiscursive expressions (I'm/we're saying, I'm/we're not saying, etc.). Our central claim is that these 'saying' expressions are pragmatic devices by which speakers claim 'all along' to have held a consistent argumentative standpoint, one that continues through the discussion unless changed for good reasons. Through close analysis of a series of discourse examples, we show how these discourse markers are used to display continuity, deflect counterarguments, and acknowledge the force of counterarguments while preserving continuity. In a concluding section we reflect critically on the use of these continuity markers with regard to four pragmatic functions that they potentially serve: to specify and clarify argumentative standpoints, to acknowledge a presumption of standpoint continuity, to acknowledge a normative expectation that discussion participants should have standpoints, and to avoid overt disagreement while saving face.     

Why Is It Now?

Adolf Grünbaum, following J.J.C. Smart, has argued that the A-Theory of time is untenable due to its inability to answer the question, uniquely attending the A-theory, as to why it is now 2000. I argue, however, that Grünbaum's explication of the question's meaning makes the question a triviality. But there may be lurking here a somewhat different question, which is meaningful on a A-Theory of time, the answer to which may have surprising implications concerning the past infinitude of time.     

Effects of violent movies and trait hostility on hostile feelings and aggressive thoughts

The General Affective Aggression Model [Anderson CA, Deuser WE, DeNeve KM (1995): Personality and Social Psychology Bulletin 21:434–448; Anderson CA, Anderson KB, Deuser WE (1996): Personality and Social Psychology Bulletin 22:366–376] suggests that violent movies may increase aggression by increasing hostile feelings and the accessibility of aggressive thoughts. It also suggests that trait hostility may similarly influence affect and cognition. Experiment 1 explored the effects of viewing violent movie clips on affect and cognition. Participants who viewed a violent movie clip later reported higher levels of state hostility than did those who viewed a nonviolent clip. Experiment 2 added trait hostility to the design as a potentially important individual difference variable. The state hostility results of Experiment 1 were replicated. In addition, the relative accessibility of aggressive thoughts was increased by the violent clip, but only for low irritable participants. Discussion focused on the relevance to aggressive behavior. Aggr. Behav. 23:161–178, 1997. © 1997 Wiley-Liss, Inc.