Kripke's Second Paragraph of Philosophical Investigations 201

The received view of Kripke's Wittgenstein on Rules and Private Language is that it fails as an interpretation because, inter alia, it ignores or overlooks what Wittgenstein has to say in the second paragraph of Philosophical Investigations (PI) 201. In this paper, I demonstrate that the paragraph in question is in fact fully accommodated within Kripke's reading, and cannot therefore be reasonably utilised to object to it. In part one I characterise the objection; in part two I explain why it fails; in part three I suggest why commentators might have been motivated to offer it; and in part four I claim that two commentators who have offered it also imply otherwise.     

The perception of false self scale for adolescents: Reliability,validity, and longitudinal relationships with depressive and anxious symptoms

A scale assessing generalized false self‐perceptions (Perceptions of False Self, POFS) was developed and tested across three studies involving a total of 331 adolescents (11–16 years). In Study 1, interviews were conducted to develop items for the scale. In Study 2, psychometric techniques were used to derive a scale composed of 16 items. Study 2 also assessed the validity of the scale: depressive symptoms were found to increase POFS across 10 weeks, whereas false self‐perceptions had a reciprocal effect on anxiety. In Study 3, the convergent validity of the POFS scale was established. Overall, the evidence suggests that the POFS scale is a reliable and valid measure of generalized false self‐perceptions.     

Intermittency in human manual tracking tasks

We confirm Craik's (1947) observation that the human manual1y tracking a visual target behaves like an intermittent servo-control1er. Such tracking responses are indicative of "sampled" negative-feedback control but could be the result of other, continuous, mechanisms. Tracking performance therefore was recorded in a task in which visual feedback of the position of the hand-held joystick could be eliminated. Depriving the subjects of visual feedback led to smoother tracking and greatly reduced the signal power of their responses between 0.5-1.8 Hz. Their responses remained intermittent when they used feedback of their own position but not of the target to track a remembered (virtual) target. Hence, intermittency in tracking behavior is not exclusively a signature of visual feedback control but also may be a sign of feedback to memorized waveforms. Craik's (1947) suggestion that the intermittency is due to a refractory period following each movement was also tested. The errors measured at the start of each intermittent response, during tracking of slow waveforms, showed evidence of a small error deadzone (measuring 0.7 cm on the VDU screen or 0.80 degrees at the eye). At higher target speeds, however, the mean size of starting errors increased, and the upper boundary of the distribution of starting error was close to that expected of a refractory delay of approximately 170 ms between responses. We consider a model of the control system that can fit these results by incorporating an error deadzone within a feedback control loop. We therefore propose that the initiation of intermittent tracking responses may be limited by a positional error deadzone and that evidence for a refractory period between successive corrective movements can be satisfied without evoking an explicit timing or sampling mechanism.     

Is the cerebellum a smith predictor?

The motor system may use internal predictive models of the motor apparatus to achieve better control than would be possible by negative feedback. Several theories have proposed that the cerebellum may form these predictive representations. In this article, we review these theories and try to unify them by reference to an engineering control model known as a Smith Predictor. We suggest that the cerebellum forms two types of internal model. One model is a forward predictive model of the motor apparatus (e.g., limb and muscle), providing a rapid prediction of the sensory consequences of each movement. The second model is of the time delays in the control loop (due to receptor and effector delays, axonal conductances, and cognitive processing delays). This model delays a copy of the rapid prediction so that it can be compared in temporal register with actual sensory feedback from the movement. The result of this comparison is used both to correct for errors in performance and as a training signal to learn the first model. We discuss evidence that the cerebellum could form both of these models and suggest that the cerebellum may hold at least two separate Smith Predictors. One, in the lateral cerebellum, would predict the movement outcome in visual, egocentric, or peripersonal coordinates. Another, in the intermediate cerebellum, would predict the consequences in motor coordinates. Generalization of the Smith Predictor theory is discussed in light of cerebellar involvement in nonmotor control systems, including autonomic functions and cognition.     

The Determinants of Mock Jurors' Verdicts in a Rape Case1

The determinants of verdicts in a rape case were examined. Pretrial attitudes (rape empathy, juror bias, belief in a just world, and authoritarianism) were measured to ascertain both the intercorrelations among the attitudes and their predictive value of verdicts. The eye contact (staring, avoiding, or random) of the alleged rape victim with the defendant was also examined. Results showed that rape empathy was predictive of verdict. The eye contact of the alleged victim with the defendant also affected verdicts of female mock jurors. Specifically, when eye contact was avoided, more guilty verdicts were rendered. Furthermore, interpretation of eye contact was found to be a function of mock jurors' reported rape empathy. Specifically, subjects who reported empathy with the victim tended to interpret the victim's behavior as consistent with being raped. Finally, differences were found between high and low empathizers for the rape victim in what aspects of the trial were important to mock jurors' decisions.     

Is object texture a constraint on human prehension?: kinematic evidence

The present experiment determined whether object texture influenced the transport and grasp components of human prehension. Infrared markers placed on the index finger, thumb, and wrist were recorded using a WATSMART system. The test objects were cylindrical dowels (103 mm high, 25 mm diameter, and 150 g in weight) of various surface materials (plain metal, coated with Vaseline, and covered with coarse sandpaper). Only temporal kinematic measures were affected by texture: Movement time (ms), time after peak deceleration (ms), percentages of movement time following maximum aperture, velocity, and deceleration were all significantly greater for the slippery dowel than the normal and rough dowels. Results indicated that the increased time associated with the slippery dowel could be explained entirely by increased time between contact with the dowel and dowel lift. Thus, these results are like those of Weir, MacKenzie, Marteniuk, Cargoe, and Frazer (1991), in which object weight was shown not to affect the free-motion phase, which includes the transport and grasp components of prehension. It appears that intrinsic object properties like weight and texture affect only the finger-object interaction phase of prehension; subsequent research is needed to dissociate inertial and surface friction effects while in contact with objects     

A New Caledonian crow (Corvus moneduloides) creatively re-designs tools by bending or unbending aluminium strips

Previous observations of a New Caledonian crow (Corvus moneduloides) spontaneously bending wire and using it as a hook [Weir et al. (2002) Science 297:981] have prompted questions about the extent to which these animals 'understand' the physical causality involved in how hooks work and how to make them. To approach this issue we examine how the same subject ("Betty") performed in three experiments with novel material, which needed to be either bent or unbent in order to function to retrieve food. These tasks exclude the possibility of success by repetition of patterns of movement similar to those employed before. Betty quickly developed novel techniques to bend the material, and appropriately modified it on four of five trials when unbending was required. She did not mechanically apply a previously learned set of movements to the new situations, and instead sought new solutions to each problem. However, the details of her behaviour preclude concluding definitely that she understood and planned her actions: in some cases she probed with the unmodified tools before modifying them, or attempted to use the unmodified (unsuitable) end of the tool after modification. Gauging New Caledonian crows' level of understanding is not yet possible, but the observed behaviour is consistent with a partial understanding of physical tasks at a level that exceeds that previously attained by any other non-human subject, including apes.     

Rearing practices and impulsivity/hyperactivity symptoms in relation to inflated responsibility and obsessive‐compulsive symptoms

Smári, J., Rúrik Martinsson, D., & Einarsson, H. (2010). Rearing practices and impulsivity/hyperactivity symptoms in relation to inflated responsibility and obsessive‐compulsive symptoms. Scandinavian Journal of Psychology, 51, 392–397. The aim of the study was to investigate potential precursors of inflated responsibility (responsibility attitudes) and obsessive‐compulsive (OCD) symptoms. It was argued that both parental overprotection and impulsivity, separately and in interaction with each other, contribute to inflated responsibility and OCD symptoms. In a large sample of young adults (N = 570), self‐report measures of OCD symptoms (OCI‐R), responsibility attitudes (RAS), anxiety/depression (HADS), rearing practices (EMBU), present and past impulsivity/hyperactivity symptoms (IMP/HY) were administered. Overprotection as well as IMP/HY were found to predict OCD symptoms as well as inflated responsibility. Finally, a significant interaction was found between IMP/HY and overprotection with regard to both OCD symptoms and inflated responsibility. This effect reflected that IMP/HY was more strongly related to OCD symptoms and responsibility in people who had not been overprotected than in people who had been. Conversely overprotection was related to OCD symptoms and responsibility in people low but not in people high in IMP/HY. The results seem to indicate that the inadequacy between offer and need for parental control may play a role in the development of OCD symptoms.     

Monocular and Binocular Vision in the Control of Goal-Directed Movement

In the present research the authors examined the time course of binocular integration in goal-directed aiming and grasping. With liquid-crystal goggles, the authors manipulated vision independently to the right and left eyes of 10 students during movement preparation and movement execution. Contrary to earlier findings reported in catching experiments (I. Olivier, D. J. Weeks, K. L. Ricker, J. Lyons, & D. Elliott, 1998), neither a temporal nor a spatial binocular advantage was obtained in 1 grasping and 2 aiming studies. That result suggests that, at least in some circumstances, monocular vision is sufficient for the precise control of limb movements. In a final aiming experiment involving 3-dimen- sional spatial variability and no trial-to-trial visual feedback about performance, binocular vision was associated with greater spatial accuracy. Binocular superiority appeared to be most pronounced when participants were unable to adjust their limb control strategy or procedure on the basis of terminal feedback about performance.