We know from the work of Robert Doty (1965, 1969), which was inspired by a study done on dogs (Baer 1905), that when electrical pulses are delivered to two cortical sites in monkeys that after some training an association is established between the two sites such that stimulation of the visual cortex evokes a muscle twitch as though the stimulation were being delivered to the motor cortex (also see: Bartlett, Doty 2005). Data suggest that in the absence of the hippocampus, information contained within different neocortical regions cannot be merged (see Footnote 1). Indeed, associations cannot be made between two stimuli that activate different neocortical areas (a tone and an air-puff) presented in succession, once the hippocampus is damaged (Kim, Thompson et al. 1995). All language learning requires that words are linked (and not overlapped) so that a listener can discriminate each word distinctly. Patient HM who lacked a hippocampus could both deliver speech and comprehend speech when engaged in dialogue (Corkin 2002). This means that the hippocampus is not necessary for the retrieval of language when engaged in dialogue. However, patient HM would not be able to add new words to his vocabulary or learn a new language (Corkin 2002). Furthermore, in the absence of the hippocampus one’s creative linguistic abilities are abolished: all hippocampal patients, including patient HM, have great difficulty narrating a story from memory (Corkin 2002; Hassabis et al. 2007ab). Thus, in the absence of the hippocampus, electrical stimulation of different sites in the neocortex—such as stimulation of the visual cortex and the motor cortex (Baer 1905; Bartlett, Doty et al. 2005; Doty 1965, 1969)—will not be associated. In other words, Chomsky’s ‘Merge’ cannot occur without the hippocampus (Chomsky 1965).
Footnote 1: The detection response as evoked by electrical stimulation of the neocortex is mediated by descending projections originating from the deepest layers of the neocortex (Logothetis et al. 2010; Rutledge and Doty 1962; Tehovnik and Slocum 2013). We would suggest that it is these descending projections that transmit the detection signal to the hippocampal formation.
As per the research about permanent memory without hippocampus is not possible in 2014(noble price). The patient with short term memory had been diagnosed with damaged hippocampus. The signal form entorhinal cortex goes to hippocampus but not store. The grid cell and place cell were not coordinating for spatial structure and grid structure.
Hi Edward,
Thanks for the question!
Hippocampus is a fundamental region of the CNS and as you know is the data storage base. However, your question is general.
My reply would be, I think it depends on the evolution caliber of the animal. Chomsky's merge in a panoramic view, and not necessarily the parameters he chose for his specific study design and hypothesis, can be applied in various other study designs and with primitive animals with no Prefrontal Cortex and/or developed Hippocampus. Just my opinion!
By the way, Prefrontal Cortex in conjunction with the Hippocampus and Nucleus Accumbens are the essence in what we implicate as the Hippocampus' role. The trio work together not the Hippocampus all by itself.
Dear Dr. Kashi.
Our goal for the book is to integrate the workings of the hippocampus, neocortex, and cerebellum, which are found in all vertebrates, and in humans these three structures collectively account for 98% of the neurons in the brain (Herculano-Houzel 2009). We believe that the 98% will give us maximal explanatory power for behaviors such as language, as well as other oculo- and skeletomotor programs, which we have studied in behaving primates and lower behaving mammals using a variety of neurophysiological methods common to systems neuroscience. We will dedicate a chapter on the basal ganglia/accumbens, which will discuss the wonderful work of Hikosaka and colleagues. The prefrontal cortex, of course, is part of the neocortex, and is connected to the frontal eye fields for maximal ocular and skeletal control, such as reading and writing via the forelimb representation of M1.
Cheers,
Ed Tehovnik.
Dear Edward,
Thank you for the promisingly great work. I have no idea how you found one of my qualifications but pls only refer to me by my name, as I you. Those qualifications were not for my promotion but to follow my role model the beloved Socrates and serving humanity.
I am pleased that you, and the team which you belong to, understand that brain wiring is "all together".
In the 20th century everything was needed to be dissected and isolated and that was the way to cognitively understand. But once all were dissected (and they are still being dismantled in sub particle level and to my delight because my research was based on sub particle analysis some 23 yrs. ago and for which I was mocked) the need is to take a panoramic look at it because "all of it" works together and not just at cortical level or even the CNS or NS. One hint: Embryonic path/process from 4 weeks onward tells the whole story in "a mathematical language" and that is how we should take a look at the body, in my opinion.
All the very best to you and your colleagues' efforts and vision!
I’m an undergraduate student and I find incredibly interesting the idea of relating Merge to the hippocampus. But if only humans have Merge, should we also say that the difference between animals and us has to do with a different organisation or composition of the hippocampus?
I would say it has more to do with the vocal apparatus and that it is directly innervates by the neocortex for maximal control over the muscles (this is the same for songbirds). This is also true for why we can write: the neocortical motor area for the hand directly connects to the motor neurons in the spinal cord to control the hand muscles. All this has been known for over 100 years going back to Sherrington (1906).
Sorry for being unclear, I was trying to express a different point. Considering Merge as the primary element of Faculty of Language in Narrow sense (Berwick e Chomsky, 2016), could we say that this lies in hippocampus? As a result, if Merge makes the difference between animals and us in terms of syntax, this difference is due to a different structure or organisation of the hippocampus
I think the uniqueness of humans has more to do with the neocortex since damage here through stroke abolishes language: the information transmitted by the hippocampus can no longer be put into long-term storage. Of course the neurons in the hippocampus must be able to transmit Merge-type associations for language to happen. Interestingly all vertebraces have a hippocampus which is part of the telencephalon, the structure that stores conscious, declarative information, whether it’s lsnguage or some other behavioral process. In this regard, the importance of the cerebellum should not be underestimated: the electric fish has an enormous cerebellum and it communicates with other electric fish using a type of Morse code based on electrical pulses. Do electric fish exhibit Merge? This is worth investigating.
Enormously interesting, thank you so much for being clear and accurate. Could you also suggest some works-if they exist- about the possibility of finding Merge in electrical fish? I'm really interested and I've never heard about that before. As a student I'm not too informed so l studied only something about birdsong but I was quite convinced by Berwick's analysis explaining that it cannot be regarded as a form of syntax).
The Merge idea for electric fish was my wild guess, but I will send you a nice paper on electric fish. The paper is not on my iPad yet, so it will involve some file transfers but you will have it shortly.
I have attached the file that you might download on the electric fish....
Perfect, I’m sincerely grateful for your help. I’ll keep reading your precious contributions
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