An Experiment upon Repeated Reproduction

The author presented dwarf hamsters (Phodopus campbelli) and golden hamsters (Mesocricetus auratus) with conspecific and inanimate signals for food. Both species approached a cardboard stimulus that predicted food. The dwarf hamsters engaged in high levels of social contact directed toward a conspecific conditioned stimulus for food, but the golden hamsters did not. The author also presented dwarf hamsters with a conspecific signal that did not indicate food, and the levels of social behaviors that they directed toward it were significantly lower. These results suggest the presence of a social component in the dwarf hamster feeding system and are consistent with previous findings that the social transmission of food preferences occurs more readily in dwarf hamsters than in golden hamsters.     

A Test of the Overconfidence Phenomenon Using Audio Signals

The existence of the overconfidence phenomenon was examined using a signal detection paradigm. Fifty-five participants were asked to decide whether they heard a signal or noise only, and to rate how certain they were of their decisions. The results confirmed the existence of overconfidence as well as the “hard-easy” effect.     

Coordination of Eye and Leg Movements During Visually Guided Stepping

In the present study, 2 related hypotheses were tested: first, that vision is used in a feedforward control mode during precision stepping onto visual targets and, second, that the oculomotor and locomotor control centers interact to produce coordinated eye and leg movements during that task. Participants' (N = 4) eye movements and step cycle transition events were monitored while they performed a task requiring precise foot placement at every step onto irregularly placed stepping stones under conditions in which the availability of visual information was either restricted or intermittently removed altogether. Accurate saccades, followed by accurate steps, to the next footfall target were almost always made even when the information had been invisible for as long as 500 ms. Despite delays in footlift caused by the temporary removal (and subsequent reinstatement) of visual information, the mean interval between the start of the eye movement and the start of the swing toward a target did not vary significantly (p > .05). In contrast, the mean interval between saccade onset away from a target and a foot landing on that target (stance onset) did vary significantly (p < .05) under the different experimental conditions. Those results support the stated hypotheses.     

Eye-Hand Coordination in Rhythmical Pointing

The authors investigated the relation between hand kinematics and eye movements in 2 variants of a rhythmical Fitts's task in which eye movements were necessary or not necessary. P. M. Fitts's (1954) law held in both conditions with similar slope and marginal differences in hand-kinematic patterns and movement continuity. Movement continuity and eye—hand synchronization were more directly related to movement time than to task index of difficulty. When movement time was decreased to fewer than 350 ms, eye—hand synchronization switched from continuous monitoring to intermittent control. The 1:1 frequency ratio with stable π/6 relative phase changed for 1:3 and 1:5 frequency ratios with less stable phase relations. The authors conclude that eye and hand movements in a rhythmical Fitts's task are dynamically synchronized to produce the best behavioral performance.     

How do Motor Systems Deal with the Problems of Controlling Three-Dimensional Rotations?

Rotations are fundamental to motor control, not only for orienting to stimuli but also in the joint articulations that underlie translational movements. Studying three-dimensional (3-D) rotations of the simplest joint system, the eye, has provided general insights into the neural control of movement. First, in selecting one 3-D eye orientation for each two-dimensional (2-D) gaze direction, the oculomotor system generates a behavior called Listing's law that constrains eye position to a 2-D plane, Listing's plane. This selection is made internally by an inverse kinematic transformation called the Listing's law operator. Second, the oculomotor system incorporates the inherent multiplicative relationship between rotational velocity and position to generate the 3-D movement and position commands required by Listing's law. Finally, the coordinate systems for these commands appear to align with Listing's plane rather than with anatomic structures. Recent investigations have revealed similar behavioral constraints in the orientations of the head and arm, suggesting that the neural mechanisms for Listing's law may have analogues in many motor systems.     

Comment on “Retention Characteristics of Motor Short-Term Memory Cues”

Marteniuk (1973) used negative results, which may be attributed to a lack of power, to question the adequacy of variable error as a measure of forgetting. He also used these negative results, along with constant error results which were consistent with the Laabs (1971, 1973) model of motor memory, to reject parts of the model related to variable error. Caution is advised when interpreting negative results and interchanging dependent measures.     

Handedness and Hemispheric Asymmetry in the Control Of Movements

This study investigated the influence of hemispheric specialization of function on the motor performance of the hands. Right-handed (n=17), ambidextral (n=21), and ambisinistral (n=12) subjects performed Fitts' (1954) reciprocal tapping task under two conditions with each hand. Conditions had the same index of difficulty but differed in movement precision. The left hand of righthanders was superior in the condition requiring the greatest amount of preprogramming. Conversely, the right hand was not superior in the condition having the greatest demand for feedback control. For ambidextrals, left-hand superiority in the relatively preprogrammed condition was also revealed. Ambisinistrals showed no significant difference between conditions with either hand. The results partially support the hypothesis that the motor performance of the hands mirrors the dominant processing mode of their contralateral hemisphere. Failure to find supportive evidence in ambisinistrals is consistent with the contention that they lack hemispheric specialization of function.     

Mirroring,imitation, identification: the sense of self in relation to the mother's internal world

The phenomenon of neonatal imitation, and the use of mutual imitation by mother and baby in the service of attunement, are considered in relation to psychoanalytic theories of mirroring, imitation and identification. Material from infant observation and from the treatment of two children on the autistic spectrum is discussed in terms of the suggestion that developmental imitation implies a perceived position of balance between the external baby and the mother's supposed internal occupant. This is seen as making possible introjective identification and assimilation, with the enrichment of the sense of identity, in contrast to the kind of imitation involving mimicry, in which adhesive or projective identification may be operative.     

‘Wholeness,Dignity and the Ageing Self’: A Conversation Between Philosophy and Theology

SUMMARY

Winifred Wing Han Lamb: My philosophical interest straddles the areas of education, religion and theology. As a teacher involved in school philosophy programs, I have also been interested in the philosophy of childhood and particularly in the recurring notion of the ‘whole child’ in education. In considering what ‘wholeness’ could mean for children's education, I have also been led to consider what meaning it holds for the self through the ‘changing scenes’ of life, especially in the face of the challenges of ageing.

The notion of ‘wholeness’ holds an intuitive appeal and invites articulation of the deep truths of our faith with respect to persons in all ‘sorts and conditions.’ In section one of this chapter, I attempt that articulation. But this conversation needs to be complementary. Our chapter is the beginning of a dialogue between philosophy and theology in which both affirm the ageing self in the light of the human search for wholeness and dignity.

Heather Thomson: My theological research into humanity as an image of God led me to inquire about the way in which we could speak meaningfully of ageing and dying in terms of imaging God. This challenged how God-likeness was to be understood in relation to glory, honour and power, terms associated with imaging God and exerting dominion. In searching for a theological view of the self that would confer dignity on the ageing, I was led into conversation with various philosophies of the self, some very helpful for my task.

It seems to me that, if ageing people are to be counted as having dignity and worth, and not discounted, then one's theory of the human person was significant. In pondering the issue, it appeared that a conversation between philosophy and theology would be fruitful. Hence, this joint paper. We each speak from our own discipline but find resonance with each other's work. We see this as a first step in a constructive conversation.     

Waldo reveals cultural differences in return fixations

ABSTRACT

Humans routinely perform visual search towards targets to adapt to the environment. These sequences of ballistic eye movements are shaped by a combination of top–down and bottom–up factors. Recent research documented that human observers display cultural-specific fixation patterns in a range of visual processing tasks. In particular, eye movement strategies extracting information from faces clearly differs between Western Caucasian (WC) and East Asian (EA) observers. However, whether such cultural differences are also present for visual scene processing remains debated. To this aim, we recorded the eye movements of WC and EA observers while they were solving visual search problems parametrically varying in difficulty: Where’s Waldo. Both groups had a comparable familiarity with the Waldo books reaching a comparable level of accuracy in target detection. Both cultural groups also showed a comparable temporal effect on inhibition of return, with longer fixation durations when saccades were performed to a return location compared to other locations. Westerners, however, located Waldo faster than Easterners. Interestingly, this modulation of speed was likely related to differences occurring on the low-level mechanisms of spatial inhibition of return, with EA observers returning more often to previously visited locations than the WC observers. This suboptimal eye movement strategy in the Easterners might be engendered by their cultural perceptual bias consisting in? a greater use of extra-foveal information. Overall, our data point towards the existence of a subtle, but significant difference in the processing of visual scenes across observers from different cultures during active visual search.