Dr Magda Osman Room 2.25 Office hours Mondays Mental Causation Dr Magda Osman Room 2.25 Office hours Mondays

Learning outcomes Have knowledge of the different types of relationships the mind has to the brain (connection to the mind/body problem) Understand the issues regarding intentionality and its connection to mental causation Have a good understanding of the empirical methods used to examine causation (Libet study, and current replications)

Relationship between Mental & Physical How are minds and bodies related? Interactive substance Mental and Physical substances interact directly with each other Psychophysical parallelism Mental and Physical substances exist in parallel, and do not interact with each other

Are interactive substance and Psychophysical parallelism… Monist positions Dualist positions

Problem 1 –Mental causing physical changes If the mental has causal influence over the physical—then there must be causal laws connecting mental phenomena with physical phenomena (i.e., causal laws that govern the mental’s interaction with the physical). But has psychology/philosophy found any such laws? NO Unless we treat the mental state as a physical event for it to have any kind of causal power – in which we still need laws to explain psychophysical behaviour (Donald Davidson, 1963)

Problem 2 –Mental causing physical changes Causal Closure Principle – “[N]o causal chain involving a physical event will ever cross the boundary of the physical into the nonphysical” Mental to physical – violates the causal closure principle unless mental events and properties are somehow brought into the physical domain. But if they are part of the physical domain, doesn’t that mean that they are physical properties and events? Epiphenomenalism Reductionist – only care about neural states (which correspond with what is a mental event – e.g. pain) – which are the physical events in the brain that have causal power.

Problem 3 –Mental causing physical changes Mental causation is a psychological trick, not observable in reality (an argument akin to Hume’s argument) Tea making can be viewed as a simple Stimulus-Response set up, without having to posit complex ideas such as agency. Dennett’s (1971, 2006) Intentional stance systems theory makes this very point. He distinguishes the physical level (e.g., laws of physics) from the design (e.g., biological, chemical) and intentional (e.g., attribution of beliefs, desires) level of description of any system (human, animal, artefact).

Intentionality I Intentionality is an essential concept for agency because the assignment of actions is intimately linked to intentions. The intention is the basis for the action, and the action can cause bodily movements such as using my finger to flick the switch of the kettle causing the water to boil. (intentions are actions plans) (Mele, 1992; Pacherie, 2008; Osman, 201, 2014)

Intentionality II What happens when we are performing actions that are automatic – i.e. when we become practiced in a sport – our intention to act might be slower than performing the action? Some (Hornsby, 1980; Mele, 2009) propose that we can assign special status to bodily movements as actions; for instance, by saying that they are closest to (i.e. proximal) the intention than other actions. However… there is a problem….

So what? For psychology and neuroscience, Agency (intentionality) and consciousness are bounded Why is this an issue? Some psychologists claim (e.g., Libet, 1985; Soon et al, 2008; Verbaarschot et al, 2015) that the representational content of an intention should include lower level components such as motor schemata and neuromuscular activity

Libet (early studies in the 80’s) Benjamin Libet conducted a series of EEG experiments to determine if there is electrical activity in the brain before a bodily action. He was able to show that there was an electrical signal build-up in the brain approx 500 msc before a physical movement was carried out. So half a second before I move my finger, there is an electrical build up in some neurons of the brain. This electrical build up was given the name "readiness potential" by Libet.

E.g. Libet’s study (1979) I More or less simultaneously the experimenter 1) stimulated a brain region such that the subject felt a tickle in her left hand. 2) stimulated the right hand directly. The subject had to decide where they felt the stimulation first, in the right hand or in the left hand or at the same time. It was possible for the experimenter to shift the onsets  of the stimulations

E.g. Libet’s study (1979) I Libet predicted that – it should take approx 500 msc to prompt a conscious experience (since it needs always approximately a half second before an external stimulus can enter into consciousness). However, the outcome was completely unexpected: The stimulation of the brain and the stimulation of the skin were experienced simultaneously if the stimulation of the hand started a half second earlier

Implications In case of the external stimulation of the skin our 'conscious mind' subtracts 500msc and predates the subject's conscious experience.  (alternates the time line of conscious experience In this way, we experience the outer world in the correct way – i.e. as it happens in real time. It takes a while until we experience  a event in the outer world. However, our 'conscious mind' dates it back and we think we experience the world in the temporally right moment.

Libet (studies in the 90’s) I In the more advanced experiment Libet put electrodes on the heads of his subjects and asked them to observe a very fast moving clock. he then asked them to move their wrists whenever they wanted to but note the time at which the "desire to move the wrist" came into their minds. So there were three time measurements for each subject:   1) The time of the build up of the electrical signals in the brain ( this is the readiness potential) [electromyogram of the muscles] 2) The time when the conscious wish to act occurs in the brain ( this is now called Libet's W time) [the clock time] 3) The actual time of the physical movement or action. [EEG]

E.g. Libet’s study II

Libet (studies in the 90’s) II Libet had found that the readiness potential is generated upto -500 ms before the button press. Conscious will to act occurred about -200 ms before the action 300 ms before you know about it consciously, your conscious desire to move has been caused by electrical signals building up This has been taken to imply that – at least in the case for simple motor tasks there seems to be that mental states don’t have causal efficacy.

Conclusions drawn from Libet’s studies Our brain initiates a 'voluntionary act' unconsciously.  This is not a conscious decision but unconscious processes are influencing our decision making. This conclusions directly contradicts our (conscious) common sense: Consciousness is unfaithful. From the voluntionary act to the action itself (lifting a finger) it takes about 200 ms (myogram of the muscles). Is this enough time for a consciousness to veto actions?

I am entirely convinced Unsure I am not at all unconvinced Does the evidence from Libet’s study convince you that our conscious experiences are tricking us into thinking we have control over our actions? I am entirely convinced Unsure I am not at all unconvinced

Haggard, Clark and Kalogeras (2002) Libet investigated the relation between the time people “felt” decisions for conscious actions/events. Another related issues is the perception of events in time compared with the actual real time course of events for example the timing judgment of pressing a key and the (delayed) occurrence of an event

Haggard, Clark and Kalogeras (2002) Libet’s work (a) Haggard et al’s Work (b)

Haggard, Clark and Kalogeras (2002) E1 Does our perception of when an event occurs depend on whether we caused it? E1. – Condition A - S’s judged the onset of a tone by reporting the corresponding position of a rapidly moving clock hand. (observation) E1. – Condition B – S’s judged the onset of a tone, but in this case when they pressed a key it caused a tone to follow 250 ms later. (action) They found that when the tone was causally linked to the subjects’ keypress, subjects judged the tone to occur 46 ms earlier than if these events had occurred independently of their actions.

Haggard, Clark and Kalogeras (2002)

Explanation Hume identified Temporal and Spatial continguity as factors that facilitating the judgment of causality. So, the closer together in space and time events are (particularly when the cause is our intervention on the world) as compared to spatio-temporally distant events, then they will be perceived as causally related. With certain assumptions about the prior probabilities, it follows from Bayes’ equation that events known to be causally related are more likely to be close in time and space than unrelated events. P(Cause (e1, e2) | CloseTime(e1, e2)) > P(Cause (e1, e2) | DistantTime(e1, e2)) ==>  (with certain assumptions about the prior probabilities) P(CloseTime(e1, e2) | Cause (e1, e2)) > P(DistantTime(e1, e2) | Cause (e1, e2))

Different explanations for re-ordering We re-organize the events so that it looks like effects happens shortly after our actions because: Haggard et al (2002) we compress the time between actions and subsequent sensory events, such that all sensations following actions appear to draw closer to the actions (intentional binding). Stetson et al (2006) suggest that the perceived timing of sensory events shifts with respect to the perceived timing of actions

Mental causation summary In general, our system is designed to make our experiences of the world coherent: Moreover, the basic framework it operates under is to give the impression that our 1. our intentions cause actions 2. our action have effects on the world 3. there is a correspondence between intentions, actions and effects Even when there are temporal lags between actions and events our system recalibrates the temporal order – which implies that that temporal order judgments between motor acts and sensory events are constantly changing in order to maintain causality assessments.