Reasoning deficits among illicit drug users are associated with aspects of cannabis use

Deficits in deductive reasoning have been observed among ecstasy/polydrug users. The present study seeks to investigate dose-related effects of specific drugs and whether these vary with the cognitive demands of the task. One hundred and five participants (mean age 21.33, SD 3.14; 77 females, 28 males) attempted to generate solutions for eight one-model syllogisms and one syllogism for which there was no valid conclusion. All of the one-model syllogisms generated at least one valid conclusion and six generated two valid conclusions. In these six cases, one of the conclusions was classified as common and the other as non-common. The number of valid common inferences was negatively associated with the aspects of short-term cannabis use and with measures of IQ. The outcomes observed were more than simple post-intoxication effects since cannabis use in the 10 days immediately before testing was unrelated to reasoning performance. Following adjustment for multiple comparisons, the number of non-common valid inferences was not significantly associated with any of the drug-use measures. Recent cannabis use appears to impair the processes associated with generating valid common inferences while not affecting the production of non-common inferences. It is possible, therefore, that the two types of inference may recruit different executive resources, which may differ in their susceptibility to cannabis-related effects.     

Selective effects of errorful generation on recognition memory: the role of motivation and surprise

ABSTRACT

The current research examined the effects of errorful generation on memory, focusing particularly on the roles of motivation and surprise. In two experiments, participants were first presented with photographs of faces and were asked to associate four facts with each photograph. On Generate trials, the participants guessed two of the facts (Guess targets) before those correct facts, and another two correct facts (Study targets), were revealed. On the remaining Read trials, all four facts were presented without a guessing stage. In Experiment 1, participants also ranked their motivation to know the answers before they were revealed, or their surprise on learning the true answers. Guess targets were subsequently better recognised than the concurrently presented, non-guessed Study targets. Guess targets were also better recognised than Read targets, and recognition of Study and Read targets did not differ. Errorful generation also increased self-reported motivation, but not surprise. Experiment 2 showed that the results of Experiment 1 can outlive a 20-minute delay, and that they generalise to a more challenging recognition test. Together, the results suggest that errorful generation improves memory specifically for the guessed fact, and this may be linked to an increase in motivation to learn that fact.     

Quasi-realism and fundamental moral error1

A common first reaction to expressivist and quasi-realist theories is the thought that, if these theories are right, there's some objectionable sense in which we can't be wrong about morality. This worry turns out to be surprisingly difficult to make stick—an account of moral error as instability under improving changes provides the quasi-realist with the resources to explain many of our concerns about moral error. The story breaks down, though, in the case of fundamental moral error. This is where the initial worry finally sticks—quasi-realism tells me that I can't be fundamentally wrong about morality, though others can.     

Eye Metrics: An Alternative Vigilance Detector for Military Operators

Military operators in various environments such as cyber, remotely piloted aircraft, and image analysis are required to use sustained attention or vigilance for long periods. During this time they encounter lapses in attention attributable to the monotonous nature of their tasks. Mistakes during these tasks can have serious consequences. The purpose of this study was to investigate the use of an eye-tracker to detect changes in vigilance performance during a simulated cyber operator task. Twenty participants performed 4 sessions of a 40-min vigilance task while wearing an eye-tracker. Blink frequency, blink duration, PERCLOS (percentage of eye closure), pupil diameter, pupil eccentricity, pupil velocity, and signal detection all had a significant change over time (p < .05) during the task. The significant change of oculometric measurements indicates oculometrics could be used to detect changes in vigilance for military operators. Future research is needed to assess real-time effects of these oculometrics on performance, especially in a real-world setting.     

Explicit feedback maintains implicit knowledge

The role of feedback was investigated with respect to conscious and unconscious knowledge acquired during artificial grammar learning (AGL). After incidental learning of training sequences, participants classified further sequences in terms of grammaticality and reported their decision strategy with or without explicit veridical feedback. Sequences that disobeyed the learning structure conformed to an alternative structure. Feedback led to an increase in the amount of reported conscious knowledge of structure (derived rules and recollections) but did not increase its accuracy. Conversely, feedback maintained the accuracy of unconscious knowledge of structure (intuition or familiarity-based responses) which otherwise degraded. Results support a dual-process account of AGL. They suggest that implicit learning of the to-be-rejected structure at test contaminates familiarity-based classifications whereas feedback allows competing familiarity signals to be contextualised, which is incompatible with theories that consider familiarity context-insensitive.