Derek Hodgson

The First Appearance of Symmetry in the Human Lineage: Where Perception Meets Art

Abstract: Although symmetry may be important for understanding the selection of form in art over the historical period, this preference may have originally stemmed from certain basic perceptual mechanism that initially arose during prehistory. The first signs of an awareness to symmetry can be found in the archaeological record with the arrival of Acheulean handaxes, especially those dating from 500,000 years ago onwards, which are typified by a prodigious bilateral symmetry. As handaxes represent the earliest material record of an interest in symmetry by the human lineage, they provide a privileged means of understanding why this kind of form came to be valued by later human groups, particularly in relation to “art”. Although still controversial, the preference for symmetry at such an early date has been linked to various aspects of perception relating to enduring evolutionary factors. In this regard, it will be demonstrated how the preference for symmetrical Acheulean tools arose out of long standing perceptual correlates relating to ecological factors that predated the arrival of hominins.

Shamanism, phosphenes, and early art : An alternative synthesis

The proposition of Lewis-Williams and Dowson (1988, 1993) that many of the abstract marks found in Palaeolithic and Neolithic art can be put down to neurophysiological processes, as determined by shamanistic practices, has been cause for considerable debate. On the positive side, it has helped open up a fresh approach to this aspect of art by providing some valuable insights as to its probable derivation. On the negative side, it leaves open certain questions relating to cultures in which shamanism is known to be absent but the same or similar motifs are apparent. How is the persistence of analogous motifs in such cultures to be explained? There is also the problem of the growing accumulation and antiquity of geometric motifs dating to the Lower and Middle Palaeolithic. Although relying on the neurophysiological model as the underlying mechanism responsible for geometric mark-making, recent commentators, including Lewis-Williams and Dowson, have remained reticent as to the exact nature of the proposed cerebral component. This is surprising given that a detailed understanding of this mechanism could provide important insights as to how early marks might have arisen and that recent research concerning the visual cortex has provided a substantial amount of hard scientific data for analysis in this context. To rely on a neurophysiological model without any attempt at specifying the nature of the primary agent concerned involves a substantial leap of faith. This paper presents important evidence for a more profound, pervasive explanation for early abstract geometric art based upon recent neurophysiological research and a detailed description of the mechanisms involved.

Altered States of Consciousness and Palaeoart: an Alternative Neurovisual Explanation

There has been much controversy recently regarding Lewis-Williamss assertion that altered states of consciousness and shamanism can explain Palaeolithic art. Evidence now seems to be accumulating that this account is unable to provide a sustainable explanation for Upper Palaeolithic depictions. This proposition will be explored and substantiated by examining further weaknesses contained therein. Additionally, in response to claims by those defending altered states that no alternative explanation for palaeoart has been proposed as a viable alternative, it will be shown that such a description does exist but has not been given the attention it deserves because of a misplaced concern for shamanism.

More on Acheulean Tools

There seems to be some consensus in the comments on McNabb et al.’s (CA 45:653–77) paper that Acheulean tools reveal a trend beginning with an imprecise kind of symmetry and leading to more defined regularities. Recent findings on how the brain functions can help to clarify why this sequence evolved. The visuo-spatial pathway (the “where/how” dorsal system), involving visually guided action, which would have been intimately associated with the making of tools, is thought to be “blind” (Ungerleider and Mishkin 1982, Goodale et al. 1991, Milner and Goodale 1995)—that is, more concerned with the parameters underpinning visuo-spatial guidance than with the overt identity of objects. In contrast, the “what” ventral pathway, which mediates explicit visual identification, may play down or even ignore visuo-spatial factors because these are largely irrelevant for a recognition system that strives to achieve object constancy (Turnbull, Carey, and McCarthy 1997, Turnbull, Beschin, and Della Sala 1997). The “where/how” pathway is thought to culminate in the superior parietal lobe. As this area is deemed to have undergone enlargement from Homo habilis through H. erectus to modern humans (Weaver 2002), the implications are obvious in the present context. The superior parietal lobe has been shown to be particularly active when an experienced stone knapper fashions a tool (Stout et al. 2000). Its enlargement from H. habilis to modern humans helps to explain the relative ineptness of chimps in manipulating tools. The makers of late, as opposed to early, Acheulean tools were therefore probably beginning to rely more on the “what” system than on the “where/how” pathway. Turnbull and collaborators believe that the inferior parietal lobe may supply some explicit form recognition to the visuo-spatial system, especially in non-optimal conditions and when mental rotation is required. Glover (2004) has proposed that enlargement of the phylogenetically newer inferior parietal lobe in humans is devoted to planning strategies for action, whereas on-line monitoring and control continue to be mediated by the superior parietal lobe. Tool and object use in particular required that human motor planning processes become integrated with some ventral pathway functions for object identification, which seems, in humans (in contrast

Seeing the ‘Unseen’: Fragmented Cues and the Implicit in Palaeolithic Art

Palaeolithic Art is generally thought to be based primarily upon the explicit conscious aspects of recognition and memory. Recent research into perception and cognition, however, has revealed a ‘hidden’ substructure of processing, known as implicit perception and memory, that functions in a different way to overt modes of cognisance but, yet, by dovetailing with consciously defined determinants helps to define how these are structured. As the making of Palaeolithic Art would have been contingent on the perceptual/recognition/visual memory system, it is therefore admirably suited to an understanding from the standpoint of implicit processes. Here I will demonstrate how the enduring features of this art can be investigated from the perspective of implicit, or covert, psychological factors and the consequences of this approach for the genesis of this art.

The Visual Dynamics of Upper Palaeolithic Cave Art.

Franco-Cantabrian cave art continues to be the focus of much speculation but despite the many theories put forward there has been little progress in explaining the range of perplexing features of this ‘art’. Only by regarding such wide-ranging and anomalous characteristics as central to this debate might some progress as to derivation be possible. The account presented in this article will demonstrate how the many ‘contradictions’ prevailing might provide an important indication as to provenance that can be explained through an understanding of the shifting nature of visual imagery in the context of the everyday lives of Upper Palaeolithic communities. This will be based on the notion that the visual world as perceived can be disrupted by certain types of psychological effects that can be subsequently triggered by particular kinds of stimulus cues and evocative situations.

Decoding the Blombos Engravings, Shell Beads and Diepkloof Ostrich Eggshell Patterns

The debate regarding the status of the Blombos ochre engravings and shell beads for gauging the timeline of when cognitive abilities and symbolic intent appeared has been controversial. This is mainly due to the fact that what is referred to as symbolic is often too loosely defined and is therefore attributed to artefacts in an indiscriminate way. Recent evidence from various concurrent sites in southern Africa, including Blombos, provide the opportunity for a more nuanced analysis of the probable level of symbolic intent and how this relates to neuro-cognitive precursors. In what follows, it will be shown that, although some of the southern African artefacts do indeed demonstrate particular kinds of ‘symbolic’ intent, others need to be approached with caution. Data from the visual brain is presented that provides crucial evidence as to the appropriate level of intent suggested by the engravings and shell beads from the southern Africa context.

Are there alternative adaptive strategies to human pro-sociality? The role of collaborative morality in the emergence of personality variation and autistic traits

ABSTRACT Selection pressures to better understand others’ thoughts and feelings are seen as a primary driving force in human cognitive evolution. Yet might the evolution of social cognition be more complex than we assume, with more than one strategy towards social understanding and developing a positive pro-social reputation? Here we argue that social buffering of vulnerabilities through the emergence of collaborative morality will have opened new niches for adaptive cognitive strategies and widened personality variation. Such strategies include those that that do not depend on astute social perception or abilities to think recursively about others’ thoughts and feelings. We particularly consider how a perceptual style based on logic and detail, bringing certain enhanced technical and social abilities which compensate for deficits in complex social understanding could be advantageous at low levels in certain ecological and cultural contexts. ‘Traits of autism’ may have promoted innovation in archaeological material culture during the late Palaeolithic in the context of the mutual interdependence of different social strategies, which in turn contributed to the rise of innovation and large scale social networks.

The visual brain and the early depiction of animals in Europe and Southeast Asia

Abstract The recent discovery that iconic depictions in caves on the Indonesian island of Sulawesi are more ancient than those from Upper Palaeolithic Europe raises questions as to when such images first arose and why the graphic outcomes from the two locations are so similar. In this paper, we show that these questions can be addressed by exploiting the extensive research carried out over the recent past on the psychology of perception and the neuroscience of the visual brain that allows the proper place of iconic depictions in understanding cognitive evolution to be determined.

Costly signalling, the arts, archaeology and human behaviour

ABSTRACT The role of the arts has become crucial to understanding the origins of ‘modern human behaviour’ but is highly controversial as it is not clear why the arts evolved and persisted. I argue that the arts evolved as a by-product of biological traits and expressions of gene culture co-evolution that facilitated group cohesion through costly signalling that led to increasing but, ultimately, unsustainable population densities. This paper therefore strives to defend the concept of costly signalling by demonstrating that the arts, by way of the extended phenotype, served as a device that initially enhanced group cohesion but which could also potentially lead to the demise of a community.