Rats and pigs seem to be able to discriminate anxiety from its absence generalizably across causes with a learned behaviour, like pressing a lever when they would apparently feel anxious.[1] In other words, it seems like they can be taught to tell us what they’re feeling in ways unnatural and non-instinctive to them. To me, the difference between this and human language is mostly just a matter of degree, i.e. we form more associations and form them more easily, and we do recursion.
Graziano (2020, pdf), an illusionist and the inventor of Attention Schema Theory, also takes endogenous/top-down/voluntary attention control to be evidence of having a model (schema) of one’s own attention.[2] Then, according to Nieder (2022), there is good evidence for the voluntary/top-down control of attention (and working memory) at least across mammals and birds, and some suggestive evidence for it in some fish.
And I would expect these to happen in fairly preserved neural structures across mammals, at least, including humans.
I also discuss desires and preferences in other animals more here and here.
Carey and Fry (1995) showed that pigs generalize the discrimination between non-anxiety states and drug-induced anxiety to non-anxiety and anxiety in general, in this case by pressing one lever repeatedly with anxiety, and alternating between two levers without anxiety (the levers gave food rewards, but only if they pressed them according to the condition). Many more such experiments were performed on rats, as discussed in Sánchez-Suárez, 2016, summarized in Table 2 on pages 63 and 64 and discussed further across chapter 3.
Rats could discriminate between the injection of the anxiety-inducing drug PTZ and saline injection, including at subconvulsive doses. Various experiments with rats and PTZ have effectively ruled out convulsions as the discriminant, further supporting that it’s the anxiety itself that they’re discriminating, because they could discriminate PTZ from control without generalizing between PTZ and non-anxiogenic drugs, and with the discrimination blocked by anxiolytics and not nonanxiolytic anticonvulsants.
Rats further generalized between various pairs of anxiety(-like) states, like those induced by PTZ, drug withdrawal, predator exposure, ethanol hangover, “jet lag”, defeat by a rival male, high doses of stimulants like bemegride and cocaine, and movement restraint.
But could such results merely reflect a “blindsight-like” guessing: a mere discrimination response that need not reflect underlying awareness? After all, as we have seen for S.P.U.D. subjects, decerebrated pigeons can use colored lights as DSs (128), and humans can use subliminal visual stimuli as DSs [e.g., (121)]. We think several refinements could reduce this risk.
I would expect that checking which brain systems are involved and what their typical functions are could provide further evidence. The case for other mammals would be strongest, given more preserved functions across them, including humans.
Any creature that can endogenously direct attention must have some kind of attention schema, and good control of attention has been demonstrated in a range of animals including mammals and birds (e.g., Desimone & Duncan, 1995; Knudsen, 2018; Moore & Zirnsak, 2017). My guess is that most mammals and birds have some version of an attention schema that serves an essentially similar function, and contains some of the same information, as ours does. Just as other animals must have a body schema or be condemned to a flailing uncontrolled body, they must have an attention schema or be condemned to an attention system that is purely at the mercy of every new sparkling, bottom-up pull on attention. To control attention endogenously implies an effective controller, which implies a control model.
What do you think of the following evidence?
Rats and pigs seem to be able to discriminate anxiety from its absence generalizably across causes with a learned behaviour, like pressing a lever when they would apparently feel anxious.[1] In other words, it seems like they can be taught to tell us what they’re feeling in ways unnatural and non-instinctive to them. To me, the difference between this and human language is mostly just a matter of degree, i.e. we form more associations and form them more easily, and we do recursion.
Graziano (2020, pdf), an illusionist and the inventor of Attention Schema Theory, also takes endogenous/top-down/voluntary attention control to be evidence of having a model (schema) of one’s own attention.[2] Then, according to Nieder (2022), there is good evidence for the voluntary/top-down control of attention (and working memory) at least across mammals and birds, and some suggestive evidence for it in some fish.
And I would expect these to happen in fairly preserved neural structures across mammals, at least, including humans.
I also discuss desires and preferences in other animals more here and here.
Carey and Fry (1995) showed that pigs generalize the discrimination between non-anxiety states and drug-induced anxiety to non-anxiety and anxiety in general, in this case by pressing one lever repeatedly with anxiety, and alternating between two levers without anxiety (the levers gave food rewards, but only if they pressed them according to the condition). Many more such experiments were performed on rats, as discussed in Sánchez-Suárez, 2016, summarized in Table 2 on pages 63 and 64 and discussed further across chapter 3.
Rats could discriminate between the injection of the anxiety-inducing drug PTZ and saline injection, including at subconvulsive doses. Various experiments with rats and PTZ have effectively ruled out convulsions as the discriminant, further supporting that it’s the anxiety itself that they’re discriminating, because they could discriminate PTZ from control without generalizing between PTZ and non-anxiogenic drugs, and with the discrimination blocked by anxiolytics and not nonanxiolytic anticonvulsants.
Rats further generalized between various pairs of anxiety(-like) states, like those induced by PTZ, drug withdrawal, predator exposure, ethanol hangover, “jet lag”, defeat by a rival male, high doses of stimulants like bemegride and cocaine, and movement restraint.
However, Mason and Lavery (2022) caution:
I would expect that checking which brain systems are involved and what their typical functions are could provide further evidence. The case for other mammals would be strongest, given more preserved functions across them, including humans.
Graziano (2020, pdf):